【笔记】深拷贝、浅拷贝

1、浅拷贝 Object.assign(target, source1, source2)

var initObj = {
	name: "xiaoming",
	age: 12,
	sex:undefined,
	addAge: function () {
		return ++this.age;
	}
}
var tempObj = {};
Object.assign(tempObj, initObj);
tempObj.age = 20;
console.log(initObj);//{name: "xiaoming", age: 12, sex: undefined, addAge: ƒ}
console.log(tempObj);//{name: "xiaoming", age: 20, sex: undefined, addAge: ƒ}

2、浅拷贝JSON.parse(JSON.stringify())

var initObj = {
	name: "xiaoming",
	age: 12,
	sex:undefined,
	addAge: function () {
		return ++this.age;
	}
}
var tempObj = JSON.parse(JSON.stringify((tempObj, initObj)));
tempObj.age = 35;
console.log(initObj);//{name: "xiaoming", age: 12, sex: undefined, addAge: ƒ}
console.log(tempObj);//{name: "xiaoming", age: 35}

3.深拷贝，封装一个函数

function deepCopy(data) {
	if (typeof data !== 'object' || data == null) {
		return data;
	}
	//解释：不是对象(即是一个单独的数字、字符串、undefined、function)又或者是单独一个null，则直接返回该值
	var newData = data instanceof Array ? [] : {};
	for (var key in data) {
		newData[key] = typeof data[key] === 'object' ? (data[key] === null ? null : deepCopy(data[key])) : data[key];
		//解释：判断各个值，如果是 数字、字符串、undefined、function则直接赋值，是对象就再判断是否为null，为null则直接赋值，否则再次作为一个对象进来得到返回值后赋值
	}
	return newData;
}
var initObj = {
	name: "xiaoming",
	age: 30,
	sex:undefined,
	addAge: function () {
		return ++this.age;
	}
}
var tempObj = deepCopy(initObj);
tempObj.age = 35;
console.log(initObj);//{name: "xiaoming", age: 30, sex: undefined, addAge: ƒ}
console.log(tempObj);//{name: "xiaoming", age: 35, sex: undefined, addAge: ƒ}