5.浅拷贝与深拷贝

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<!DOCTYPE html><html lang="en"><head>    <meta charset="UTF-8">    <title>Title</title></head><body><script>    <!--浅拷贝-->     ES6   Object.assign(...)方法实现了浅拷贝//    要小心处理引用拷贝---对象类型（对象 函数   数组）拷贝就是引用拷贝  改变子类 就会改变父类    function extendCopy(p) {        var c = {};        for(var i in p){            c[i] = p[i];        }        c.uber = p;        return c;    }    var shape = {        name:'shape',        toString:function () {            return this.name;        }    }    var twoDee = extendCopy(shape);    twoDee.name = '2D shape';    twoDee.toString = function () {        return this.uber.toString() + ','+ this.name;    };    var triangle = extendCopy(twoDee);    triangle.name = 'Triangle';    triangle.getArea = function () {        return this.side * this.height/2;    };    triangle.side = 5;    triangle.height = 10;    triangle.getArea();       //输出   2 5    triangle.toString();      //输出   “shape, 2D shape,Triangle”//     深拷贝  解决了浅拷贝拷贝引用的问题    function deepCopy(p,c) {        var c = c || {};        for(var i in p){            if(typeof p[i] === 'object'){                c[i] = (p[i].constructor === Array) ? [] : {};                deepCopy(p[i],c[i]);            }else{                c[i] = p[i];            }        }        return c;    }    var parent = {        numbers:[1,2,3],        letters:['a','b','c'],        obj:{            prop:1        },        bool:true    };    var mydeep = deepCopy(parent);    var myshallow = extendCopy(parent);    mydeep.numbers.push(4,5,6);       //输出    6    mydeep.numbers;                   //输出    [1,2,3,4,5,6]    parent.numbers;                   //    [1,2,3]    myshallow.numbers.push(10);       //   4    myshallow.numbers;                //[1,2,3,10]    parent.numbers;                   //[1,2,3,10]    mydeep.numbers;                   //[1,2,3,4,5,6]</script></body></html>
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