js的内存

    <script>
        function Person(name,age){
            this.name = name;
            this.age = age;
        }
        var p = new Person("张三",18);
        var p1 = p;
        p1.name = "李四";
        console.log(p);
        console.log(p1);
    </script>

<script>
    var num = 10;
    var num1 = num;
    num = 20;
    console.log(num);  //20
    console.log(num1); //10
</script>

<script>
    //全局变量
    var num = 10;
    function f1(){
        //局部变量  函数里面是可以声明和全局变量同名的变量，一旦声明之后，函数里面用的就是自己的
        var num = 60;
        console.log(num);
    }
    f1();
    console.log(num);
</script>

<script>
    //全局变量
    var num = 10;
    function f1(num){
        //函数中的参数其实函数内部的信息
        num = 60; //这里面修改的仅仅只是自己的num，而不是全局变量
        console.log(num);
    }
    f1(num);
    console.log(num);
</script>

    <script>
        var num1 = 55;
        var num2 = 66;
        function f1(num,num1){
            num = 100;
            num1 = 100;
            num2 = 100;
        }
        f1(num1, num2);
        console.log(num1); //55
        console.log(num2); //100
        console.log(num);  //not defined
    </script>