Detailed explanation of the mutual conversion between js objects and JSON format strings in JavaScript

This article mainly introduces the mutual conversion of js objects and JSON format strings in JavaScript. It has certain reference value. Interested friends can refer to it.

First let’s take a look at the string in JSON format in js

var JSONStr1 = "{\"name\" : \"张三\"}";

Note that the following writing method is not the string in JSON format in js. It's just a js string.

var JSONStr2 = "{'name' : '张三'}";

Let’s look at the definition of string in JSON syntax: is a collection of any number of Unicode characters surrounded by double quotes, using Backslash escaping. A character is a single character string.

Let’s take a look at how to convert a JSON format string into a JS object in js. (

var jsObj3 = eval("(" + JSONStr1 + ")");
var jsObj4 = JSON.parse(JSONStr1);

For specific reasons why it is recommended to use the second method, please refer to: http://www.php.cn/

In addition, a word of caution The js object converted using these two methods should be "a js object that conforms to the JSON data format", which means that its attributes are in quotes. This is just a guess on my part, because if the characters in the JSON format The string is represented as follows:

var JSONStr1 = "{\"f[name]\" : \"张三\"}";

Then the properties of the converted JS object must be added with quotation marks, because the properties of the js object without quotation marks can only use letters. Numbers, underscores and $ symbols indicate that when using other symbol attributes, quotation marks are required, so it is not wrong to add quotation marks to the attributes in JS object literal notation. In addition, if the string in JSON format is as shown above, then. The converted js object cannot use jsObj4.f[name] to obtain the value of f[name]. Instead, use jsObj4['f[name]'] because there are special characters. Readers should pay attention to this point. If you have any objections, you can submit them to me

Let’s take a look at the conversion of js objects and JSON format strings in js. Below I have prepared several groups of js objects for explanation:

<input type="button" value="测试按钮1" onclick="testJson();"/>

<script type="text/javascript">
  //(1) 这是一个js对象
  var jsObj1 = {
    name : "张三"
  }
  //（2）这是一个内部带有方法js对象。
  var jsObj2 = {
    name : "张三",
    func : function(){
      alert("hello");
    }
  }
  //（3）这是一个符合JSON数据格式的js对象
  var jsonObj = {
    "name" : "张三",
    "age" : 10,
    "remark" : {"high" :170,"address" : "beijingshi"}
  }
  // js数组对象
  var jsArray = [
    {name : "张三"},
    {"age" : 10}
  ]

  function testJson(){

    var JSONstr1 = JSON.stringify(jsObj1);
    var JSONstr2 = JSON.stringify(jsObj2);
    var JSONstr3 = JSON.stringify(jsonObj);
    var JSONstr4 = JSON.stringify(jsArray);
    alert(JSONstr1);
    alert(JSONstr2);
    alert(JSONstr3);
    alert(JSONstr4);

  }

Look at the contents of the pop-up box:

##                                                                                                                                                                           3) 　　　　　　　　　　　　　　　　 (4)

The execution results of (1), (3), and (4) are: stringify() of JSON parser function for js There is no restriction if the object conforms to the JSON format, and the js object can be converted into a JSON format string. The execution result of

(2) shows that if there is no value represented by JSON in the js object (such as function and undefined) will be excluded.

The above is the entire content of this article. I hope it will be helpful to everyone's learning. I also hope that everyone will support the PHP Chinese website.

More detailed explanations of js in JavaScript. For articles related to the conversion of objects and JSON format strings, please pay attention to the PHP Chinese website

!