How to use the ES6 spread operator

This time I will show you how to use the ES6 expansion operator. The expansion operator has the following four functions. This article will give you a good analysis.

1. Expand the array

//展开数组
let a = [1,2,3,4,5],
b = [...a,6,7];
console.log(b);
//打印出来的值[1, 2, 3, 4, 5, 6, 7]

2. Copy the array

//数组的拷贝
var c = [1, 2, 3];
var d = [...c]; 
d.push(4); 
console.log(d);
//打印出来的值[1, 2, 3, 4]

3. Merge the array

//数组的合并
var j = [7, 1, 2];
var k = [5, 0, 8];
j = [...k, ...j];
console.log(j)
//打印出来的值[5, 0, 8, 7, 1, 2]

4. Calling the spread function

//展开函数调用
function fn(a,b,c,d){
 console.log(a+b+c+d);
}
var p=[1,9,3,,6];
let result=fn(5,...p);开函数的调用
//打印出来的值18

The spread operator (spread) is three dots (...), which converts an array ||like array| |Convert a string to a comma-separated sequence. This guy is used to operate arrays and take out all the things in the array

I believe you have mastered the method after reading the above introduction. For more exciting information, please pay attention to other related articles on the PHP Chinese website!

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