js校验规则--去空格、加空格

// 拼接空格，每4位加一个空格
let bankAccount = ‘6228888888888888888‘;
let blank_value = bankAccount.replace(/\s/g,‘‘).replace(/(.{4})/g,"$1 ").trim();
console.log(blank_value);

// 字符串去中间空格
let value = ‘ab cd efg‘;
let temp = value.replace(/[ ]/g, "");
console.log(temp);

let str = ‘  abcdefg   ‘;
let new_str = str.trim();
console.log(new_str);