Javascript引用不变

Question

我想了解以下

        var obj1 = {
            value: "first value"
        };

        var obj2 = {
            value: "second value"
        };

        var  obj3 = obj2;

        function change(obj1, obj2) {
            obj1.value = "asdasd";
            obj2 = "lol";
        }

        change(obj1, obj2);

        console.log("1",obj1.value);//"asdasd"
        console.log("2",obj2.value);//"secondvalue"

为什么只改变obj1.value ??

Answer 1

当您将参数obj2更改为指向字符串时，您将丢失对传递给它的对象的引用。

     function change(obj1, obj2) {
        obj1.value = "asdasd";
        // You are only changing the parameter obj2 not a sub property of the object it contained.
        obj2 = "lol";
    }