什么是“......”数组中的（三点）表示法是什么意思？

我不明白 ... 符号究竟是什么。

I don't understand what the ... notation does exactly.

我尝试了一个简单的例子用Babel来理解它（ 查看示例 ），但似乎：

I tried a simple example with Babel to understand it (view the example), but it seems that:

ES6语法

let myArray = [1, 2, 3, ...18];

console.log(myArray); // [1, 2, 3]
console.log(myArray[4]);// undefined
console.log(myArray.length); // 3

与此ES5语法相同：

"use strict";

function _toConsumableArray(arr) { 
    if (Array.isArray(arr)) { 
        for (var i = 0, arr2 = Array(arr.length); i < arr.length; i++) {
             arr2[i] = arr[i];
        }
        return arr2;
     } else { 
        return Array.from(arr); 
     } 
}

var myArray = [1, 2, 3].concat(_toConsumableArray(18));

console.log(myArray); // [1, 2, 3]
console.log(myArray[4]); // undefined
console.log(myArray.length); // 3

但是：此代码的作用是什么？因为输出（ console.log ）与此代码（ES5）相同：

BUT: What does this code do? Because the output (console.log) is the same as in this code (ES5):

var myArray = [1,2,3];

console.log(myArray); // [1, 2, 3]
console.log(myArray[4]);// undefined
console.log(myArray.length); // 3

... 18 $ c $是什么c>符号是什么意思？