slice（）到对象数组没有返回引用？

Question

Please help me, I am really confused with the slice() of javascript. I have read the documentation of Array.prototype.slice() . It said :

For object references (and not the actual object), slice copies object references into the new array. Both the original and new array refer to the same object. If a referenced object changes, the changes are visible to both the new and original arrays.

In this code, I use slice() to actual object but it still returns a reference

var arObj = [
    { 'name': 'Jon',  'age': 24 },
    { 'name': 'Mark', 'age': 32 },
    { 'name': 'Kacy', 'age': 22 }
];

// use splice to copy array of objects into second variable
var ar2 = arObj.slice();

// modify property value in copy
ar2[1].name = 'Bill';

// view original (also modified)
console.log( arObj[1].name ); // Bill

And the second code, it doesn't:

let data = this.state.data.slice(); //If you don't have the slice function, it will return a reference.
console.log(this.state.data);
data.reverse();

if I try to reverse or change value of data, the value of (this.state.data) won't change. This is the structure of this.state.data:

https://i.stack.imgur.com/94emV.png

Answer 1

Thank you all for helping me, and sorry for my stupid bug. The reverse() function won't affect the original array. It will be only affected if you mutate the value of one or more items in the reference array.