我想弄清楚如何验证这样格式化的数字:XXXX或XXXX-XXXX
i tried
/^'d{4}(-{1}'d{4})?/i
，但它只验证XXXX-XXXX格式，而不验证XXXX。
Thanks in advance
验证时不需要捕获组:
^'d{4}(?:-'d{4})?$
^'/' /' /^'/' /^^^
| | | | | | | ||`-- end of string
| | | | | | | |`-- previous is optional (non-capture group of `-` and 4 numbers 0-9)
| | | | | | | `-- end of non-capture group
| | | | | | `-- exactly 4 of previous (any number 0-9)
| | | | | `-- any number 0-9
| | | | `-- just `-`
| | | `-- non-capture group
| | `-- exactly 4 of previous (any number 0-9)
| `-- any number 0-9
`-- start of string
试试这个:
/'d{4}(-'d{4})?/
演示:http://regexr.com?356sf
我试了这个:
^'d{4}(-'d{4})?
: http://regexpal.com/
你可以在第一个区域写正则表达式，在第二个区域测试数字。
适用于1234和1234-1234(任何数字)