1.0 隨機(jī)數(shù)的獲取 返回true/false

//true/false 概率各50%
const randomBoolean =()=> Math.random() >0.5
console.log(randomBoolean())

2.0 判斷時間是否是工作日

const isWorkDay = (date)=>date.getDay() %6 !==0
console.log(isWorkDay(new Date(2021,1,23)))//false 
console.log(isWorkDay(new Date(2021,1,25)))//true 

3.0 反轉(zhuǎn)字符串

const reverse = (str)=>str.split('').reverse().join('')
console.log(reverse('helloworld')) //dlrowolleh

4.0 檢查當(dāng)前tab 是否在前臺 (document.hidden)

const isBowserInterview = () => document.hidden;
console.log(isBowserInterview()) //控制臺打印 返回的為false

5.0 檢查數(shù)字是否是奇數(shù)

const isEven =num => num%2===0
console.log(isEven(2)) //true
console.log(isEven(3)) //false

6.0 從日期中獲取時間 (toTimeString()方法)

const isDateStr = date => date.toTimeString().slice(0,8)
console.log(isDateStr(new Date(2021,1,25,11,06,0))) //11:06:00

7.0 檢查當(dāng)前用戶是否是蘋果設(shè)備 (非蘋果返回false,是蘋果為true)

const isAppleDevicer =  /Mac|iPod|iPhone|iPad/.test(navigator.platform);
console.log(isAppleDevicer) 

8.0 滾動頁面到頂部

const goToTop  = ()=> window.scrollTo(0,0)
goToTop () //調(diào)用該方法 頁面即滾動到頂部

9.0 獲取所有參數(shù)的平均值

const  average = (...args)=>args.reduce((a,b)=>a+b)/(args.length)
console.log(average(1,2,3,4)) //2.5

10.if 多條件判斷

function X(x){
    // if(x==='abc'||x==='def' || x==='ghk'){
    //     console.log(x)
    // }
    //優(yōu)化之后
    if(['abc','def','hjk'].includes(x)){
        console.log(x)
    }
}
let x = new X("abc") //abc
let x1 = new X("def") //def
let x2 = new X("hjk") //hjk

11.if ... else

let a =10
// if(a>10){
//     test = false
// }else{
//     test = true
// }
//優(yōu)化之后
let test = a>10;
console.log(test) //true

12. 函數(shù)調(diào)用

function test1(){
    console.log('test1')
}
function test2(){
    console.log('test2')
}
var test3 =1
// if(test3===1){
//     test1()
// }else{
//     test2()
// }

test3 === 1? test1():test2(); //test1
等價于 
（test3===1?test1:test2)() //test1