Modify the code and function descriptions

Signed-off-by: Njiangkai43 <jiangkai43@huawei.com>

zh-cn/application-dev/reference/apis/js-apis-convertxml.md

@@ -47,21 +47,27 @@ convertToJSObject(xml: string, options?: ConvertOptions) : Object
 **示例：**
 
 ```js
-let xml =
-    '<?xml version="1.0" encoding="utf-8"?>' +
-    '<note importance="high" logged="true">' +
-    '    <title>Happy</title>' +
-    '    <todo>Work</todo>' +
-    '    <todo>Play</todo>' +
-    '</note>';
-let conv = new convertxml.ConvertXML()
-let options = {trim : false, declarationKey:"_declaration",
-    instructionKey : "_instruction", attributesKey : "_attributes",
-    textKey : "_text", cdataKey:"_cdata", doctypeKey : "_doctype",
-    commentKey : "_comment", parentKey : "_parent", typeKey : "_type",
-    nameKey : "_name", elementsKey : "_elements"}
-let result = JSON.stringify(conv.convertToJSObject(xml, options));
-console.log(result);
+try {
+    let xml =
+        '<?xml version="1.0" encoding="utf-8"?>' +
+        '<note importance="high" logged="true">' +
+        '    <title>Happy</title>' +
+        '    <todo>Work</todo>' +
+        '    <todo>Play</todo>' +
+        '</note>';
+    let conv = new convertxml.ConvertXML()
+    let options = {
+        trim: false, declarationKey: "_declaration",
+        instructionKey: "_instruction", attributesKey: "_attributes",
+        textKey: "_text", cdataKey: "_cdata", doctypeKey: "_doctype",
+        commentKey: "_comment", parentKey: "_parent", typeKey: "_type",
+        nameKey: "_name", elementsKey: "_elements"
+    }
+    let result = JSON.stringify(conv.convertToJSObject(xml, options));
+    console.log(result);
+} catch (e) {
+    console.log(e.toString());
+}
 // 输出(宽泛型)
 // {"_declaration":{"_attributes":{"version":"1.0","encoding":"utf-8"}},"_elements":[{"_type":"element","_name":"note","_attributes":{"importance":"high","logged":"true"},"_elements":[{"_type":"element","_name":"title","_elements":[{"_type":"text","_text":"Happy"}]},{"_type":"element","_name":"todo","_elements":[{"_type":"text","_text":"Work"}]},{"_type":"element","_name":"todo","_elements":[{"_type":"text","_text":"Play"}]}]}]}
 ```

zh-cn/application-dev/reference/apis/js-apis-util.md

@@ -26,7 +26,7 @@ format(format: string,  ...args: Object[]): string
 | 参数名  | 类型     | 必填 | 说明           |
 | ------- | -------- | ---- | -------------- |
 | format  | string   | 是   | 式样化字符串。 |
-| ...args | Object[] | 否   | 替换式样化字符串通配符的数据。  |
+| ...args | Object[] | 否   | 替换式样化字符串通配符的数据，此参数缺失时，默认返回第一个参数。 |
 
 **返回值：**
 
@@ -69,6 +69,20 @@ let result = util.errnoToString(errnum);
 console.log("result = " + result);
 ```
 
+**部分错误码及信息示例：**
+
+| 错误码 | 信息                              |
+| ------ | -------------------------------- |
+| -1     | operation not permitted          |
+| -2     | no such file or directory        |
+| -3     | no such process                  |
+| -4     | interrupted system call          |
+| -5     | i/o error                        |
+| -11    | resource temporarily unavailable |
+| -12    | not enough memory                |
+| -13    | permission denied                |
+| -100   | network is down                  |
+
 ## util.callbackWrapper
 
 callbackWrapper(original: Function): (err: Object, value: Object )=>void
@@ -126,17 +140,23 @@ promisify(original: (err: Object, value: Object) => void): Function
 **示例：**
 
   ```js
-  function aysnFun(str1, str2) {
-    if (typeof str1 === 'object' && typeof str2 === 'object') {
-      return str2
-    } else {
-      return str1
-    }
-  }
-  let newPromiseObj = util.promisify(aysnFun);
-  newPromiseObj({ err: "type error" }, {value:'HelloWorld'}).then(res => {
-    console.log(res);
-  })
+function fun(num, callback) {
+   if (typeof num === 'number') {
+      callback(null, num + 3);
+   } else {
+      callback("type err");
+   }
+}
+
+const addCall = util.promisify(fun);
+(async () => {
+   try {
+      let res = await addCall(2);
+      console.log(res);
+   } catch (err) {
+      console.log(err);
+   }
+})();
   ```
 
 ## util.randomUUID<sup>9+</sup>
@@ -243,7 +263,7 @@ printf(format: string,  ...args: Object[]): string
 | 参数名 | 类型 | 必填 | 说明 |
 | -------- | -------- | -------- | -------- |
 | format | string | 是 | 式样化字符串。 |
-| ...args | Object[] | 否 | 替换式样化字符串通配符的数据。 |
+| ...args | Object[] | 否 | 替换式样化字符串通配符的数据，此参数缺失时，默认返回第一个参数。 |
 
 **返回值：**