js 值引用和地址引用

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测试

1. 数字类型

		var m = 1000;
		var n = m;
		n++;
		console.log(n);	// 1001
		console.log(m); // 1000

2. 字符串类型

		var str = "qwer";
		var newstr = str;
		newstr += "tyu";
		console.log(newstr); // qwertyu
		console.log(str);	 // qwer

3. 布尔类型

		var bool = true;
		var newbool = bool;
		newbool = false;
		console.log(newbool); // false
		console.log(bool);	  // true

4. 数组类型

		var arr = [1,2,3,4,5];
		var newarr = arr;
		var y = newarr.splice(1,3);
		console.log(y);		 // [2, 3, 4]
		console.log(newarr); // [1, 5]
		console.log(arr);	 // [1, 5]

		var arr = [1,2,3,4,5];
		var newarr = [];
		for(var x in arr){
			newarr.push(arr[x]);
		}
		var y = newarr.splice(1,3);
		console.log(y); 	 // [2, 3, 4]
		console.log(newarr); // [1, 5]
		console.log(arr); 	 // [1, 2, 3, 4, 5]

5. 对象类型

		var obj = {"name":"zhangsan","age":10,"sex":"nan"};
		var newobj = obj;
		newobj.name = "lisi";
		console.log(newobj); // {name: "lisi", age: 10, sex: "nan"}
		console.log(obj);	 // {name: "lisi", age: 10, sex: "nan"}

		var obj = {"name":"zhangsan","age":10,"sex":"nan"};
		for(var x in obj){
			newobj[x] = obj[x];
		}
		newobj.name = "lisi";
		console.log(newobj); // {name: "lisi", age: 10, sex: "nan"}
		console.log(obj);	 // {name: "zhangsan", age: 10, sex: "nan"}

结论

综上测试所得：

数字、字符串、布尔类型的为原始类型，是值引用
数组、对象类型为地址引用
值引用 可以深拷贝
地址引用 循环到原始类型方可进行深拷贝