# systemParameter
## Modules to Import
```
import parameter from '@ohos.systemParameter'
```
## Required Permissions
None
## parameter.getSync
getSync\(key: string, def?: string\)
Gets the value of the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
def
string
No
Default value
**Return Values**
Type
Description
string
System attribute value. If the specified key does not exist, the default value is returned. If no default value has been set, an empty string will be returned.
**Example**
```
try {
var info = parameter.getSync("test.parameter.key");
console.log(JSON.stringify(info));
}catch(e){
console.log("getSync unexpected error: " + e);
}
```
## parameter.get
get\(key: string, callback: AsyncCallback\)
Gets the value of the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
callback
AsyncCallback<string>
Yes
Callback function
**Example**
```
try {
parameter.get("test.parameter.key", function (err, data) {
if (err == undefined) {
console.log("get test.parameter.key value success:" + data)
} else {
console.log(" get test.parameter.key value err:" + err.code)
}});
}catch(e){
console.log("get unexpected error: " + e);
}
```
## parameter.get
get\(key: string, def: string, callback: AsyncCallback\)
Gets the value of the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
def
string
Yes
Default value
callback
AsyncCallback<string>
Yes
Callback function
**Example**
```
try {
parameter.get("test.parameter.key", "default", function (err, data) {
if (err == undefined) {
console.log("get test.parameter.key value success:" + data)
} else {
console.log(" get test.parameter.key value err:" + err.code)
}
});
}catch(e){
console.log("get unexpected error:" + e)
}
```
## parameter.get
get\(key: string, def?: string\)
Gets the value of the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
def
string
No
Default value
**Return Values**
Type
Description
Promise<string>
Promise, which is used to obtain the result asynchronously
**Example**
```
try {
var p = parameter.get("test.parameter.key");
p.then(function (value) {
console.log("get test.parameter.key success: " + value);
}).catch(function (err) {
console.log("get test.parameter.key error: " + err.code);
});
}catch(e){
console.log("get unexpected error: " + e);
}
```
## parameter.setSync
setSync\(key: string, value: string\)
Sets a value for the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
value
string
Yes
System attribute value to set
**Example**
```
try {
parameter.setSync("test.parameter.key", "default");
}catch(e){
console.log("set unexpected error: " + e);
}
```
## parameter.set
set\(key: string, value: string, callback: AsyncCallback\)
Sets a value for the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
def
string
Yes
Default value
callback
AsyncCallback<void>
Yes
Callback function.
**Example**
```
try {
parameter.set("test.parameter.key", "testValue", function (err, data) {
if (err == undefined) {
console.log("set test.parameter.key value success :" + data)
} else {
console.log("set test.parameter.key value err:" + err.code)
}});
}catch(e){
console.log("set unexpected error: " + e);
}
```
## parameter.set
set\(key: string, def?: string\)
Sets a value for the attribute with the specified key.
**Parameters**
Name
Type
Mandatory
Description
key
string
Yes
Key of the system attribute
def
string
No
Default value
**Return Values**
Type
Description
Promise<string>
Promise, which is used to obtain the result asynchronously