JavaScript split() 方法, 用于把一个字符串分割成字符串数组。
stringObject.split(separator,how many)
用正则表达式来进行切割：可以去除多个空格
let tag = "cn bitcoin kr cc"
let tags = this.tag.trim().split(/\s+/)
//得到：tags = ["cn", "bitcoin", "kr", "cc"]
eg:
var string = "Split me into an array";
var array = [];
array = string.split("a");
document.write(array);
//Split me into ,n ,rr,y
eg:
var string = "There are many apple on the tree";
var array = [];
array = string.split("a");
document.write(array);
//There ,re m,ny ,pple on the tree