在JavaScript中引用数组的最后一个元素？

Question

In my code, I have a lot code like this:

my_array[my_array.length - 1] = sth;

Is it possible to define a simple variable to point to last element of array?like this:

var ref =  (&|*, sth like that) my_array[my_array.length - 1];
ref = sth;

Answer 1

You will have to change array prototype, and use it like below:

var arr = ['a','b','c'];

Array.prototype.last=function() {
    if(this.length >= 1) {
        return this[this.length - 1];
    }
    else {
        return null;
    }
};

arr.last();

Shuold work - you can check it in Chrome JS console.