javascript: 复制对象时的深拷贝及浅拷贝(chrome 105.0.5195.125)

一，js代码

<html>
<head>
    <meta charset="utf-8"/>
    <title>测试</title>
</head>
<body>
  <button onclick="assign()">无效:变量直接赋值</button><br/><br/><br/>
  <button onclick="assignCopy()">浅拷贝:assign复制对象</button><br/><br/>
  <button onclick="operatorCopy()">浅拷贝:对象展开运算符复制对象</button><br/><br/><br/>
  <button onclick="eachCopy()">深拷贝:遍历属性复制对象</button><br/><br/>
  <button onclick="jsonCopy()">深拷贝:json复制对象</button><br/><br/>
<script>
    //直接赋值复制对象
  function assign() {
        let obj1 = {name:'老刘',age:30,info:{address:'hebei',mobile:'13888888888'}}
        let obj2 = obj1;
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
         obj1.name = '老王测试';
         obj1.info.mobile = '13899999999';
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
        console.log('是否同一个对象：');
        console.log(obj1 === obj2 );
    }

    //Object.assign复制对象
  function assignCopy() {
        let obj1 = {name:'老刘',age:30,info:{address:'hebei',mobile:'13888888888'}}
        var obj2 = Object.assign({}, obj1);
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
         obj1.name = '老王测试';
         obj1.info.mobile = '13899999999';
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
        console.log('是否同一个对象：');
        console.log(obj1 === obj2 );
    }

    //对象展开运算符复制对象
  function operatorCopy() {
        let obj1 = {name:'老刘',age:30,info:{address:'hebei',mobile:'13888888888'}}
        let obj2 = {...obj1};
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
         obj1.name = '老王测试';
         obj1.info.mobile = '13899999999';
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
        console.log('是否同一个对象：');
        console.log(obj1 === obj2 );
    }

    //用json的属性复制对象
      function jsonCopy() {
        let obj1 = {name:'老刘',age:30,info:{address:'hebei',mobile:'13888888888'}}
        let obj2 = JSON.parse(JSON.stringify(obj1));
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
         obj1.name = '老王测试';
         obj1.info.mobile = '13899999999';
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
        console.log('是否同一个对象：');
        console.log(obj1 === obj2 );
    }

    //遍历属性复制对象
    function eachCopy() {
        let obj1 = {name:'老刘',age:30,info:{address:'hebei',mobile:'13888888888'}}
        let obj2 = deepClone(obj1);
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
         obj1.name = '老王测试';
         obj1.info.mobile = '13899999999';
        console.log('obj1:');
        console.log(obj1);
        console.log('obj2:');
        console.log(obj2);
        console.log('是否同一个对象：');
        console.log(obj1 === obj2 );
    }

//函数，遍历对象的属性复制
function deepClone(obj) {
    if(obj === null) return null 
    if(typeof obj !== 'object') return obj;
    var newObj = new obj.constructor ();  //保持继承链
    for (var key in obj) {
        if (obj.hasOwnProperty(key)) {   //不遍历其原型链上的属性
            var val = obj[key];
            newObj[key] = typeof val === 'object' ? arguments.callee(val) : val; // 使用arguments.callee解除与函数名的耦合
        }
    }  
    return newObj;  
}
</script>
</body>
</html>