不同长度字符串时的javascript正则表达式

Question

我有一串数字，应该有 9 个字符，并且我有一个正则表达式，它用相同的字符串和一些空格替换该字符串；像这样的东西:

TheString = '123456789';
TheSpacedString = TheString.replace(/(\d{1})(\d{2})(\d{2})(\d{2})(\d{2})/, '$1 $2 $3 $4 $5');
TheSpacedString format is now '1 23 45 67 89'

问题是，当字符串的长度不是 9 时，格式化不起作用:例如，如果我们有这样的:

TheString = '12345';
TheSpacedString = TheString.replace(/(\d{1})(\d{2})(\d{2})(\d{2})(\d{2})/, '$1 $2 $3 $4 $5');
format should be '1 23 45'

但是，该字符串只是'12345'。我的正则表达式有什么问题？ jsFiddle 是 here

Answer 1

使用 将最后两组(或者您认为应该是可选的任意组)设为可选？

http://jsfiddle.net/yWSR2/3/

TheSpacedString = TheString.replace(/(\d{1})(\d{2})(\d{2})(\d{2})?(\d{2})?/, '$1 $2 $3 $4 $5');