ES6 Expand operator functions actual three points

1. Use array 
the let defaultColors = [ 'Red', 'Greed'] 
the let favoriteColors = [ 'Orange', 'Yellow'] 
the let fallColors = [ 'Pink', 'Blue'] 

the ES5 
defaultColors.concat (favoriteColors) 

for ES6 
[ defaultColors ..., ... favoriteColors] 


the ES5 
defaultColors.concat (favoriteColors) 
defaultColors.concat (fallColors) 

for ES6 
[... defaultColors, ... favoriteColors, ... fallColors] [ 'Purple', ... defaultColors, favoriteColors ..., ... fallColors, 'Black']         // can be placed directly in the array, may add another string

2. used in the function

ES5
function addNumber(a, b, c, d, e){
 let numbers = [a, b, c, d, e]
 retrun numbers.reduce((sum, number) => {
   retrun sum + number  
 },0)
}
console.log(addNumber(1,2,3,4,5))

ES6
function addNumber(...numbers){
 retrun numbers.reduce((sum, number) => {
   retrun sum + number  
 },0)
}
console.log(addNumber(1,2,3,4,5))

　　

It recommended that the code in the editor view, would be more obvious