银行卡号四位空格格式化效果基于jQuery实现，有些网站需要用到让客户输入银行卡号之类的信息，这个代码可以让网站访客在输入银行卡号信息的时候能够清晰明了的看出来自己输入的信息是否正确，增加用户体验。-Bank card number four spaces formatting effect is based on jQuery to achieve, some sites will need to allow customers to enter information like bank card number, this code allows site visitors to enter the bank card information when clarity can see the information you entered is correct, increase the user experience.