includes、indexOf等的用法
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发布时间：
2021-03-08 04:04
阅读次数：
//import {a as aa, b, sum, People} from "./module.js"
// console.log(aa)
// console.log(sum(10, 15))
// let p = new People("一起设计吧")
// p.showName()
// import aa, { str }from "./module.js"
//
// console.log(aa.a)
// let p = new aa.People("一起设计吧")
// p.showName()
// console.log(str)
import * as mod from "./module.js"
console.log(mod)
console.log(mod.default)
console.log(mod.str)
let arr = ['a', 'b', NaN]
console.log(arr.indexOf("a")) // 0
console.log(arr.indexOf("b"))
console.log(arr.indexOf(NaN)) //-1
console.log(arr.includes(NaN)) //true
const arr1 = ["es6", "es7", "es8"]
console.log(arr1.includes("es6", 0)) //true
console.log(arr1.includes("es6", 1)) //false
console.log(arr1.includes("es6", -3)) //true 从后面往前面找
// includes indexOf 只能判断基本数据类型
const arr2 = ["es6", ["es7", "es8"], "es9"]
console.log(arr2.indexOf(["es7", "es8"])) //-1
console.log(arr2.includes(["es7", "es8"])) //false
console.log(arr2.includes("es7")) //false
一起设计吧
