Please [read the FAQ](https://github.com/Microsoft/TypeScript/wiki/FAQ) before logging new issues, even if you think you have found a bug.
Issues that ask questions answered in the FAQ will be closed without elaboration.
## 2. Search for Duplicates
[Search the existing issues](https://github.com/Microsoft/TypeScript/issues?utf8=%E2%9C%93&q=is%3Aissue) before logging a new one.
## 3. Do you have a question?
The issue tracker is for **issues**, in other words, bugs and suggestions.
If you have a *question*, please use [Stack Overflow](http://stackoverflow.com/questions/tagged/typescript), [Gitter](https://gitter.im/Microsoft/TypeScript), your favorite search engine, or other resources.
Due to increased traffic, we can no longer answer questions in the issue tracker.
## 4. Did you find a bug?
When logging a bug, please be sure to include the following:
* What version of TypeScript you're using (run `tsc --v`)
* If at all possible, an *isolated* way to reproduce the behavior
* The behavior you expect to see, and the actual behavior
You can try out the nightly build of TypeScript (`npm install typescript@next`) to see if the bug has already been fixed.
## 5. Do you have a suggestion?
We also accept suggestions in the issue tracker.
Be sure to [check the FAQ](https://github.com/Microsoft/TypeScript/wiki/FAQ) and [search](https://github.com/Microsoft/TypeScript/issues?utf8=%E2%9C%93&q=is%3Aissue) first.
In general, things we find useful when reviewing suggestions are:
* A description of the problem you're trying to solve
* An overview of the suggested solution
* Examples of how the suggestion would work in various places
* Code examples showing e.g. "this would be an error, this wouldn't"
* Code examples showing the generated JavaScript (if applicable)
* If relevant, precedent in other languages can be useful for establishing context and expected behavior
# Instructions for Contributing Code
## Code of Conduct
This project has adopted the [Microsoft Open Source Code of Conduct](https://opensource.microsoft.com/codeofconduct/). For more information see the [Code of Conduct FAQ](https://opensource.microsoft.com/codeofconduct/faq/) or contact [opencode@microsoft.com](mailto:opencode@microsoft.com) with any additional questions or comments.
## Contributing bug fixes
TypeScript is currently accepting contributions in the form of bug fixes. A bug must have an issue tracking it in the issue tracker that has been approved ("Milestone == Community") by the TypeScript team. Your pull request should include a link to the bug that you are fixing. If you've submitted a PR for a bug, please post a comment in the bug to avoid duplication of effort.
## Contributing features
Features (things that add new or improved functionality to TypeScript) may be accepted, but will need to first be approved (marked as "Milestone == Community" by a TypeScript coordinator with the message "Approved") in the suggestion issue. Features with language design impact, or that are adequately satisfied with external tools, will not be accepted.
Design changes will not be accepted at this time. If you have a design change proposal, please log a suggestion issue.
## Legal
You will need to complete a Contributor License Agreement (CLA). Briefly, this agreement testifies that you are granting us permission to use the submitted change according to the terms of the project's license, and that the work being submitted is under appropriate copyright.
Please submit a Contributor License Agreement (CLA) before submitting a pull request. You may visit https://cla.microsoft.com to sign digitally. Alternatively, download the agreement ([Microsoft Contribution License Agreement.docx](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=822190) or [Microsoft Contribution License Agreement.pdf](https://www.codeplex.com/Download?ProjectName=typescript&DownloadId=921298)), sign, scan, and email it back to <cla@microsoft.com>. Be sure to include your github user name along with the agreement. Once we have received the signed CLA, we'll review the request.
## Housekeeping
Your pull request should:
* Include a description of what your change intends to do
* Be a child commit of a reasonably recent commit in the **master** branch
* Requests need not be a single commit, but should be a linear sequence of commits (i.e. no merge commits in your PR)
* It is desirable, but not necessary, for the tests to pass at each commit
* Have clear commit messages
* e.g. "Refactor feature", "Fix issue", "Add tests for issue"
* Include adequate tests
* At least one test should fail in the absence of your non-test code changes. If your PR does not match this criteria, please specify why
* Tests should include reasonable permutations of the target fix/change
* Include baseline changes with your change
* All changed code must have 100% code coverage
* Follow the code conventions described in [Coding guidelines](https://github.com/Microsoft/TypeScript/wiki/Coding-guidelines)
* To avoid line ending issues, set `autocrlf = input` and `whitespace = cr-at-eol` in your git configuration
## Contributing `lib.d.ts` fixes
The library sources are in: [src/lib](https://github.com/Microsoft/TypeScript/tree/master/src/lib)
Library files in `built/local/` are updated by running
```Shell
jake
```
The files in `lib/` are used to bootstrap compilation and usually do not need to be updated.
#### `src/lib/dom.generated.d.ts` and `src/lib/webworker.generated.d.ts`
These two files represent the DOM typings and are auto-generated. To make any modifications to them, please submit a PR to https://github.com/Microsoft/TSJS-lib-generator
## Running the Tests
To run all tests, invoke the `runtests-parallel` target using jake:
```Shell
jake runtests-parallel
```
This run will all tests; to run only a specific subset of tests, use:
```Shell
jake runtests tests=<regex>
```
e.g. to run all compiler baseline tests:
```Shell
jake runtests tests=compiler
```
or to run a specific test: `tests\cases\compiler\2dArrays.ts`
```Shell
jake runtests tests=2dArrays
```
## Debugging the tests
To debug the tests, invoke the `runtests-browser` task from jake.
You will probably only want to debug one test at a time:
```Shell
jake runtests-browser tests=2dArrays
```
You can specify which browser to use for debugging. Currently Chrome and IE are supported:
You can debug with VS Code or Node instead with `jake runtests debug=true`:
```Shell
jake runtests tests=2dArrays debug=true
```
## Adding a Test
To add a new test case, simply place a `.ts` file in `tests\cases\compiler` containing code that exemplifies the bugfix or change you are making.
These files support metadata tags in the format `// @metaDataName: value`.
The supported names and values are the same as those supported in the compiler itself, with the addition of the `fileName` flag.
`fileName` tags delimit sections of a file to be used as separate compilation units.
They are useful for tests relating to modules.
See below for examples.
**Note** that if you have a test corresponding to a specific spec compliance item, you can place it in `tests\cases\conformance` in an appropriately-named subfolder.
**Note** that filenames here must be distinct from all other compiler testcase names, so you may have to work a bit to find a unique name if it's something common.
### Tests for multiple files
When one needs to test for scenarios which require multiple files, it is useful to use the `fileName` metadata tag as such:
```TypeScript
// @fileName: file1.ts
export function f() {
}
// @fileName: file2.ts
import { f as g } from "file1";
var x = g();
```
One can also write a project test, but it is slightly more involved.
## Managing the Baselines
Compiler testcases generate baselines that track the emitted `.js`, the errors produced by the compiler, and the type of each expression in the file. Additionally, some testcases opt in to baselining the source map output.
When a change in the baselines is detected, the test will fail. To inspect changes vs the expected baselines, use
```Shell
jake diff
```
After verifying that the changes in the baselines are correct, run
```Shell
jake baseline-accept
```
to establish the new baselines as the desired behavior. This will change the files in `tests\baselines\reference`, which should be included as part of your commit. It's important to carefully validate changes in the baselines.
**Note** that `baseline-accept` should only be run after a full test run! Accepting baselines after running a subset of tests will delete baseline files for the tests that didn't run.
TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION
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"You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License.
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4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions:
You must give any other recipients of the Work or Derivative Works a copy of this License; and
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5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions.
6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file.
7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License.
8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages.
9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability.
[](https://gitter.im/Microsoft/TypeScript?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
[TypeScript](http://www.typescriptlang.org/) is a language for application-scale JavaScript. TypeScript adds optional types, classes, and modules to JavaScript. TypeScript supports tools for large-scale JavaScript applications for any browser, for any host, on any OS. TypeScript compiles to readable, standards-based JavaScript. Try it out at the [playground](http://www.typescriptlang.org/Playground), and stay up to date via [our blog](https://blogs.msdn.microsoft.com/typescript) and [Twitter account](https://twitter.com/typescriptlang).
## Installing
For the latest stable version:
```
npm install -g typescript
```
For our nightly builds:
```
npm install -g typescript@next
```
## Contribute
There are many ways to [contribute](https://github.com/Microsoft/TypeScript/blob/master/CONTRIBUTING.md) to TypeScript.
*[Submit bugs](https://github.com/Microsoft/TypeScript/issues) and help us verify fixes as they are checked in.
* Review the [source code changes](https://github.com/Microsoft/TypeScript/pulls).
* Engage with other TypeScript users and developers on [StackOverflow](http://stackoverflow.com/questions/tagged/typescript).
* Join the [#typescript](http://twitter.com/#!/search/realtime/%23typescript) discussion on Twitter.
* Read the language specification ([docx](https://github.com/Microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.docx?raw=true), [pdf](https://github.com/Microsoft/TypeScript/blob/master/doc/TypeScript%20Language%20Specification.pdf?raw=true), [md](https://github.com/Microsoft/TypeScript/blob/master/doc/spec.md)).
This file is based on or incorporates material from the projects listed below (collectively "Third Party Code"). Microsoft is not the original author of the Third Party Code. The original copyright notice and the license, under which Microsoft received such Third Party Code, are set forth below. Such licenses and notices are provided for informational purposes only. Microsoft, not the third party, licenses the Third Party Code to you under the terms set forth in the EULA for the Microsoft Product. Microsoft reserves all other rights not expressly granted under this agreement, whether by implication, estoppel or otherwise.
DefinitelyTyped
This project is licensed under the MIT license.
Copyrights are respective of each contributor listed at the beginning of each definition file.
Provided for Informational Purposes Only
MIT License
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the ""Software""), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
* Adds a property to an object, or modifies attributes of an existing property.
* @param o Object on which to add or modify the property. This can be a native JavaScript object (that is, a user-defined object or a built in object) or a DOM object.
* @param p The property name.
* @param attributes Descriptor for the property. It can be for a data property or an accessor property.
* Adds one or more properties to an object, and/or modifies attributes of existing properties.
* @param o Object on which to add or modify the properties. This can be a native JavaScript object or a DOM object.
* @param properties JavaScript object that contains one or more descriptor objects. Each descriptor object describes a data property or an accessor property.
* Finds the first substring match in a regular expression search.
* @param regexp The regular expression pattern and applicable flags.
*/
search(regexp:string):number;
/**
* Finds the first substring match in a regular expression search.
* @param regexp The regular expression pattern and applicable flags.
*/
search(regexp:RegExp):number;
/**
* Returns a section of a string.
* @param start The index to the beginning of the specified portion of stringObj.
* @param end The index to the end of the specified portion of stringObj. The substring includes the characters up to, but not including, the character indicated by end.
* If this value is not specified, the substring continues to the end of stringObj.
*/
slice(start?:number,end?:number):string;
/**
* Split a string into substrings using the specified separator and return them as an array.
* @param separator A string that identifies character or characters to use in separating the string. If omitted, a single-element array containing the entire string is returned.
* @param limit A value used to limit the number of elements returned in the array.
*/
split(separator:string,limit?:number):string[];
/**
* Split a string into substrings using the specified separator and return them as an array.
* @param separator A Regular Express that identifies character or characters to use in separating the string. If omitted, a single-element array containing the entire string is returned.
* @param limit A value used to limit the number of elements returned in the array.
*/
split(separator:RegExp,limit?:number):string[];
/**
* Returns the substring at the specified location within a String object.
* @param start The zero-based index number indicating the beginning of the substring.
* @param end Zero-based index number indicating the end of the substring. The substring includes the characters up to, but not including, the character indicated by end.
* If end is omitted, the characters from start through the end of the original string are returned.
*/
substring(start:number,end?:number):string;
/** Converts all the alphabetic characters in a string to lowercase. */
toLowerCase():string;
/** Converts all alphabetic characters to lowercase, taking into account the host environment's current locale. */
toLocaleLowerCase():string;
/** Converts all the alphabetic characters in a string to uppercase. */
toUpperCase():string;
/** Returns a string where all alphabetic characters have been converted to uppercase, taking into account the host environment's current locale. */
toLocaleUpperCase():string;
/** Removes the leading and trailing white space and line terminator characters from a string. */
trim():string;
/** Returns the length of a String object. */
readonlylength:number;
// IE extensions
/**
* Gets a substring beginning at the specified location and having the specified length.
* @param from The starting position of the desired substring. The index of the first character in the string is zero.
* @param length The number of characters to include in the returned substring.
*/
substr(from:number,length?:number):string;
/** Returns the primitive value of the specified object. */
valueOf():string;
readonly[index:number]:string;
}
interfaceStringConstructor{
new(value?:any):String;
(value?:any):string;
readonlyprototype:String;
fromCharCode(...codes:number[]):string;
}
/**
* Allows manipulation and formatting of text strings and determination and location of substrings within strings.
*/
declareconstString:StringConstructor;
interfaceBoolean{
/** Returns the primitive value of the specified object. */
valueOf():boolean;
}
interfaceBooleanConstructor{
new(value?:any):Boolean;
(value?:any):boolean;
readonlyprototype:Boolean;
}
declareconstBoolean:BooleanConstructor;
interfaceNumber{
/**
* Returns a string representation of an object.
* @param radix Specifies a radix for converting numeric values to strings. This value is only used for numbers.
*/
toString(radix?:number):string;
/**
* Returns a string representing a number in fixed-point notation.
* @param fractionDigits Number of digits after the decimal point. Must be in the range 0 - 20, inclusive.
*/
toFixed(fractionDigits?:number):string;
/**
* Returns a string containing a number represented in exponential notation.
* @param fractionDigits Number of digits after the decimal point. Must be in the range 0 - 20, inclusive.
*/
toExponential(fractionDigits?:number):string;
/**
* Returns a string containing a number represented either in exponential or fixed-point notation with a specified number of digits.
* @param precision Number of significant digits. Must be in the range 1 - 21, inclusive.
*/
toPrecision(precision?:number):string;
/** Returns the primitive value of the specified object. */
valueOf():number;
}
interfaceNumberConstructor{
new(value?:any):Number;
(value?:any):number;
readonlyprototype:Number;
/** The largest number that can be represented in JavaScript. Equal to approximately 1.79E+308. */
readonlyMAX_VALUE:number;
/** The closest number to zero that can be represented in JavaScript. Equal to approximately 5.00E-324. */
readonlyMIN_VALUE:number;
/**
* A value that is not a number.
* In equality comparisons, NaN does not equal any value, including itself. To test whether a value is equivalent to NaN, use the isNaN function.
*/
readonlyNaN:number;
/**
* A value that is less than the largest negative number that can be represented in JavaScript.
* JavaScript displays NEGATIVE_INFINITY values as -infinity.
*/
readonlyNEGATIVE_INFINITY:number;
/**
* A value greater than the largest number that can be represented in JavaScript.
* JavaScript displays POSITIVE_INFINITY values as infinity.
*/
readonlyPOSITIVE_INFINITY:number;
}
/** An object that represents a number of any kind. All JavaScript numbers are 64-bit floating-point numbers. */
* Sets the year value in the Date object using Universal Coordinated Time (UTC).
* @param year A numeric value equal to the year.
* @param month A numeric value equal to the month. The value for January is 0, and other month values follow consecutively. Must be supplied if numDate is supplied.
* @param date A numeric value equal to the day of the month.
* Parses a string containing a date, and returns the number of milliseconds between that date and midnight, January 1, 1970.
* @param s A date string
*/
parse(s:string):number;
/**
* Returns the number of milliseconds between midnight, January 1, 1970 Universal Coordinated Time (UTC) (or GMT) and the specified date.
* @param year The full year designation is required for cross-century date accuracy. If year is between 0 and 99 is used, then year is assumed to be 1900 + year.
* @param month The month as an number between 0 and 11 (January to December).
* @param date The date as an number between 1 and 31.
* @param hours Must be supplied if minutes is supplied. An number from 0 to 23 (midnight to 11pm) that specifies the hour.
* @param minutes Must be supplied if seconds is supplied. An number from 0 to 59 that specifies the minutes.
* @param seconds Must be supplied if milliseconds is supplied. An number from 0 to 59 that specifies the seconds.
* @param ms An number from 0 to 999 that specifies the milliseconds.
* Executes a search on a string using a regular expression pattern, and returns an array containing the results of that search.
* @param string The String object or string literal on which to perform the search.
*/
exec(string:string):RegExpExecArray|null;
/**
* Returns a Boolean value that indicates whether or not a pattern exists in a searched string.
* @param string String on which to perform the search.
*/
test(string:string):boolean;
/** Returns a copy of the text of the regular expression pattern. Read-only. The regExp argument is a Regular expression object. It can be a variable name or a literal. */
readonlysource:string;
/** Returns a Boolean value indicating the state of the global flag (g) used with a regular expression. Default is false. Read-only. */
readonlyglobal:boolean;
/** Returns a Boolean value indicating the state of the ignoreCase flag (i) used with a regular expression. Default is false. Read-only. */
readonlyignoreCase:boolean;
/** Returns a Boolean value indicating the state of the multiline flag (m) used with a regular expression. Default is false. Read-only. */
* @param items Additional items to add to the end of array1.
*/
concat(...items:T[][]):T[];
/**
* Combines two or more arrays.
* @param items Additional items to add to the end of array1.
*/
concat(...items:(T|T[])[]):T[];
/**
* Adds all the elements of an array separated by the specified separator string.
* @param separator A string used to separate one element of an array from the next in the resulting String. If omitted, the array elements are separated with a comma.
*/
join(separator?:string):string;
/**
* Returns a section of an array.
* @param start The beginning of the specified portion of the array.
* @param end The end of the specified portion of the array.
*/
slice(start?:number,end?:number):T[];
/**
* Returns the index of the first occurrence of a value in an array.
* @param searchElement The value to locate in the array.
* @param fromIndex The array index at which to begin the search. If fromIndex is omitted, the search starts at index 0.
* Determines whether all the members of an array satisfy the specified test.
* @param callbackfn A function that accepts up to three arguments. The every method calls the callbackfn function for each element in array1 until the callbackfn returns false, or until the end of the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Determines whether the specified callback function returns true for any element of an array.
* @param callbackfn A function that accepts up to three arguments. The some method calls the callbackfn function for each element in array1 until the callbackfn returns true, or until the end of the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Calls a defined callback function on each element of an array, and returns an array that contains the results.
* @param callbackfn A function that accepts up to three arguments. The map method calls the callbackfn function one time for each element in the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Returns the elements of an array that meet the condition specified in a callback function.
* @param callbackfn A function that accepts up to three arguments. The filter method calls the callbackfn function one time for each element in the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Gets or sets the length of the array. This is a number one higher than the highest element defined in an array.
*/
length:number;
/**
* Returns a string representation of an array.
*/
toString():string;
toLocaleString():string;
/**
* Appends new elements to an array, and returns the new length of the array.
* @param items New elements of the Array.
*/
push(...items:T[]):number;
/**
* Removes the last element from an array and returns it.
*/
pop():T|undefined;
/**
* Combines two or more arrays.
* @param items Additional items to add to the end of array1.
*/
concat(...items:T[][]):T[];
/**
* Combines two or more arrays.
* @param items Additional items to add to the end of array1.
*/
concat(...items:(T|T[])[]):T[];
/**
* Adds all the elements of an array separated by the specified separator string.
* @param separator A string used to separate one element of an array from the next in the resulting String. If omitted, the array elements are separated with a comma.
*/
join(separator?:string):string;
/**
* Reverses the elements in an Array.
*/
reverse():T[];
/**
* Removes the first element from an array and returns it.
*/
shift():T|undefined;
/**
* Returns a section of an array.
* @param start The beginning of the specified portion of the array.
* @param end The end of the specified portion of the array.
*/
slice(start?:number,end?:number):T[];
/**
* Sorts an array.
* @param compareFn The name of the function used to determine the order of the elements. If omitted, the elements are sorted in ascending, ASCII character order.
*/
sort(compareFn?:(a:T,b:T)=>number):this;
/**
* Removes elements from an array and, if necessary, inserts new elements in their place, returning the deleted elements.
* @param start The zero-based location in the array from which to start removing elements.
*/
splice(start:number):T[];
/**
* Removes elements from an array and, if necessary, inserts new elements in their place, returning the deleted elements.
* @param start The zero-based location in the array from which to start removing elements.
* @param deleteCount The number of elements to remove.
* @param items Elements to insert into the array in place of the deleted elements.
* Determines whether all the members of an array satisfy the specified test.
* @param callbackfn A function that accepts up to three arguments. The every method calls the callbackfn function for each element in array1 until the callbackfn returns false, or until the end of the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Determines whether the specified callback function returns true for any element of an array.
* @param callbackfn A function that accepts up to three arguments. The some method calls the callbackfn function for each element in array1 until the callbackfn returns true, or until the end of the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Calls a defined callback function on each element of an array, and returns an array that contains the results.
* @param callbackfn A function that accepts up to three arguments. The map method calls the callbackfn function one time for each element in the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Returns the elements of an array that meet the condition specified in a callback function.
* @param callbackfn A function that accepts up to three arguments. The filter method calls the callbackfn function one time for each element in the array.
* @param thisArg An object to which the this keyword can refer in the callbackfn function. If thisArg is omitted, undefined is used as the this value.
* Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduce method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Calls the specified callback function for all the elements in an array, in descending order. The return value of the callback function is the accumulated result, and is provided as an argument in the next call to the callback function.
* @param callbackfn A function that accepts up to four arguments. The reduceRight method calls the callbackfn function one time for each element in the array.
* @param initialValue If initialValue is specified, it is used as the initial value to start the accumulation. The first call to the callbackfn function provides this value as an argument instead of an array value.
* Determines whether two strings are equivalent in the current locale.
* @param that String to compare to target string
* @param locales An array of locale strings that contain one or more language or locale tags. If you include more than one locale string, list them in descending order of priority so that the first entry is the preferred locale. If you omit this parameter, the default locale of the JavaScript runtime is used. This parameter must conform to BCP 47 standards; see the Intl.Collator object for details.
* @param options An object that contains one or more properties that specify comparison options. see the Intl.Collator object for details.
* Determines whether two strings are equivalent in the current locale.
* @param that String to compare to target string
* @param locale Locale tag. If you omit this parameter, the default locale of the JavaScript runtime is used. This parameter must conform to BCP 47 standards; see the Intl.Collator object for details.
* @param options An object that contains one or more properties that specify comparison options. see the Intl.Collator object for details.
* Converts a number to a string by using the current or specified locale.
* @param locales An array of locale strings that contain one or more language or locale tags. If you include more than one locale string, list them in descending order of priority so that the first entry is the preferred locale. If you omit this parameter, the default locale of the JavaScript runtime is used.
* @param options An object that contains one or more properties that specify comparison options.
* Converts a date and time to a string by using the current or specified locale.
* @param locales An array of locale strings that contain one or more language or locale tags. If you include more than one locale string, list them in descending order of priority so that the first entry is the preferred locale. If you omit this parameter, the default locale of the JavaScript runtime is used.
* @param options An object that contains one or more properties that specify comparison options.
* Converts a date to a string by using the current or specified locale.
* @param locales An array of locale strings that contain one or more language or locale tags. If you include more than one locale string, list them in descending order of priority so that the first entry is the preferred locale. If you omit this parameter, the default locale of the JavaScript runtime is used.
* @param options An object that contains one or more properties that specify comparison options.
