ES6 Learning Notes (i) Array extension

extension Operators ...

1. Array extension operators convert an array to a comma-delimited sequence of arguments

Console.log (... [//1,2,3])

[' A ', ' B ',... [1,3]]//a,b,1,3

2. Extended Operations for function calls

function push (A, arr) {

A.push (... arr.);

}

****************************************************************************************

function Add (A, b) {

return a+b;

}

var arr=[1,8];

Add (... arr);

****************************************************************************************

function Add (x,y,z,n,m) {

return x+y+z+n+m;

}

var a = [[+]

Add (1,... a,3);

3. Apply extension operator instead of array

Es5

Math.max.apply (null, [1,3,4,5]);

Es6

Math.max (... [1,2,3,5])

Inserts an array into the tail of an array

1) Array.prototype.push (ARR1,ARR2);

2) arr1 = Arr1.concat (ARR2);

3) Arr1.push (... arr2);

Copying an array

arr1 = Arr.concat ()

arr1 = Arr.splice (0)

ARR1 = [... arr]

Structure Assignment

const [A, ... b] = [1,2,3,4]//a=1 b=[2,3,4]

The extension can only be used in the last

4. Convert Strings to arrays

[... ' This is str ']; ["T", "H", "I", "s", "", "I", "s", "", "s", "T", "R"]

Correctly handle strings that contain uicode codes

' x\ud83d\ude80y '. Length//4
[... ' x\ud83d\ude80y '].length//3

Invert string

Let str = ' x\ud83d\ude80y ';

Str.split ("). Reverse (). Join (')
' Y\ude80\ud83dx '

[... str].reverse (). Join (')
' y\ud83d\ude80x '

5. As long as the class array structure of the iterator interface is implemented, the extension operator can be converted to a true array

[... Nodelist]

ES6 Learning Notes (i) Array extension