如何编写正则表达式以验证特殊位置的字符？

Question

I need to validate time field in the textbox. I used this regular expression.

   var reg_exp = /^([0-9\:]*)$/;

But it allows add : any place in the text box. How to make it to add : only in the third place of the text. Ex: 11* : *34

Answer 1

Use

^\d{2}:\d{2}$

instead which matches two digits, then a colon and another two digits.

Answer 2

为了验证时间在00:00到23:59您可以使用：

/^(?:[01][0-9]|2[0-3]):(?:[0-5][0-9])$/