New features of ES6

Arrow function

Equivalent to anonymous function

• The arrow function itself has no scope （ nothing this）
• Arrowhead function this Point up one level , Context determines its this
• Basic grammar ： Parameters => The body of the function
• Arrow in function body this object , Is the object when the function is defined , Instead of the object when using the function . It was decided when the function was defined

() => return 'hello'

(a, b) => a + b

(a) => {
  a = a + 1
  return a
}

ES6 New feature arrow function syntax 、 How to use arrow function correctly _Hayley2016 The blog of -CSDN Blog _ Arrow function

`${}`

Back single quotes (``) Complete the stitching character string Not single quotes （‘’）

let str=`I love ${a}, because he is handsome.`;

let：ES6 newly added , Used to declare variables , Yes Block level scope

let [a, b, c] = [1, 2, 3];
// a = 1,b = 2,c = 3  It is equivalent to redefining variables a,b,c, The value is also more convenient 

// , =  Place holder 
let arr = [" Xiao Ming ", " floret ", " Little fish ", " Piglets "];
let [,,one] = arr; //  Small fish will be taken here 

//  Deconstruct the entire array 
let strArr = [...arr];
//  Get the entire array 
console.log(strArr);

• Deconstructing assignment is an extension of assignment operator
• Pattern matching for arrays or objects , And then assign values to the variables
• all 2021 Years. , No more learning ES6 You just out 了 —— Article, understand ES6_ Ouyang Ya's blog -CSDN Blog