Data transfer mechanism underlying stack ---

Basic data types

        let a=12
        let b=a
        b=13
        console.log(a);//12           

Reference data types

    let n={
            name:'jack'
        }
        let m=n
        m.name='rose'
        console.log(n.name);//rose

Exercise

• 1、

        let n=[10,20]
        let m=n
        let x=m
        m[0]=100
        x=[30,40]
        x[0]=200
        m=x
        m[1]=300
        m[2]=400
        console.log(n, m, x);
 //[100, 20] [200, 300, 400] [200, 300, 400]

• 2、

重点：连等号a=b=1实际上执行顺序是 a=1 b=1
    let a={
            n:1
        }
        let b=a
        a.x=a={
            n:2
        }
        console.log(a.x);//underfined
        console.log(b);//{n:1;{x:2}}