8-1 例子

1、join-split-reverse

 var str = "hello"
 // [h,e,l,l,o]
 // [o,l,l,e,h]
 // olleh
 var arr = str.split("");// 将字符串分割为数组
 console.log(arr); // ["h","e","l","l","o"]
 arr.reverse()    
 console.log(arr); // ["o","l","l","e","h"]
 var s = arr.join("")  
 console.log(s);  // 将数组转为字符串

2、切割字符

var http = "https://192.168.4.18?limit=20&offset=0"
// [{limit:20},{offset:0}]
var arr = http.split("?")[1].split("&")
var res = arr.map(item=>{
      var obj = { }
    obj[item.split("=")[0]]=item.split("=")[1]
      return obj
}
console.log(res)

var http = "https://192.168.4.18?limit=20&offset=0"
// {limit:20,offset:0}
var arr = http.split("?")[1].split("&")   //["limit=20","offset=0"]
var obj = {}
var res = arr.map(item=>{
  obj[item.split("=")[0]] = item.split("=")[1]
}
console.log(obj)