startsWith

        let str="http://it.kaiba.com"

        if(str.startsWith("http://")){
            console.log("普通网址")
        }
        else if(str.startsWith("https://")){
             console.log("加密地址")
        }

endsWith

let str="13738092889@163.com"

        if(str.endsWith("@163.com")){
            console.log("网易邮箱")
        }
        else if(str.endsWith("@qq.com")){
             console.log("qq邮箱")
        }

字符串模板

let b=12

        let str=`a${b}c`

        console.log(str) //a12c

注意

数字

  let str=`a${009001}c`

   console.log(str) //a9001c

等效于

let num=009001

        let str=`a${num}c`

        console.log(str) //a9001c

字符串

let string="STRING"

        let str=`a${string}c`

        console.log(str) //aSTRINGc

等效于

        let str=`a${"STRING"}c`

        console.log(str) //aSTRINGc