[英]javascript regular expression validate mm/dd
s="12/15"
r=/((0?[1-9])|(1[0-2])){1}\/((0?[1-9])|(1[0-9])|(2[0-9])|(3[0-1])){1}/g
s.match(r)
> ["12/1"]
I was trying to validate date format mm/dd but the matched string missed the last digit. 我试图验证日期格式mm / dd,但匹配的字符串错过了最后一位数字。
Can anyone help? 有人可以帮忙吗? Thanks, Cheng
谢谢,程
Use this regex: ^(0?[1-9]|1[0-2])/(0?[1-9]|[12][0-9]|3[01])$
使用这个正则表达式:
^(0?[1-9]|1[0-2])/(0?[1-9]|[12][0-9]|3[01])$
If you want matches in string, use word boundaries, eg: 如果你想在字符串中匹配,使用单词边界,例如:
\b(0?[1-9]|1[0-2])/(0?[1-9]|[12][0-9]|3[01])\b
(?x)
^
(
0?[1-9] # 1-9 or 01-09
|
1[0-2] # 10 11 12
)
/
(
0?[1-9] # 1-9 or 01-09
|
[12][0-9] # 10-29
|
3[01] # 30 31
)
$
Large regex: 大正则表达式:
(?x)
\b(?:
(?<month>
0?[13578]
|
1[02]
)
/
(?<day>
0?[1-9]
|
[12][0-9]
|
3[01]
)
|
(?<month>
0?[469]
|
11
)
/
(?<day>
0?[1-9]
|
[12][0-9]
|
30
)
|
(?<month>
0?2
)
/
(?<day>
0?[1-9]
|
[12][0-9]
)
)
\b
At first I removed some of your brackets. 起初我删除了一些括号。
One possibility to fix your problem is to use anchors 解决问题的一种可能性是使用锚点
^(0?[1-9]|1[0-2]){1}\/(0?[1-9]|1[0-9]|2[0-9]|3[0-1]){1}$
This would be the solution if your string is only the date. 如果您的字符串只是日期,那么这将是解决方案。 Those anchors
^
and $
ensure that the expression is matched from the start to the end. 那些锚点
^
和$
确保表达式从开始到结束匹配。
See it here online on Regexr 在Regexr上在线查看
The second possibility is to change the order in your last part. 第二种可能性是改变你最后一部分的顺序。
(0?[1-9]|1[0-2]){1}\/(1[0-9]|2[0-9]|3[0-1]|0?[1-9]){1}
Because the first part 0?[1-9]
matched your 15
your expression succeeded and that was it. 因为第一部分
0?[1-9]
与你的15
匹配,你的表达成功了,就是这样。 If we put this to the end then at first it tries to match the numbers consisting of two digits, then it matches the 15
如果我们把它放到最后,那么首先它会尝试匹配由两位数组成的数字,然后它匹配
15
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