In fact, I also have a headache regular expression, Baidu some information, summed up, here to leave a backup bar.
The question to consider: what is the legal date, the number of days per month is different, the question of a leap year ....
1. Legal Date: MSDN Rules--the date and time between 12:00:00 midnight, January 1, 01 (C.E.) December 31, 9999, and 11:59:59 in A.D. (Christian ERA)
View Http://msdn.microsoft.com/zh-cn/library/system.datetime (vs.80). aspx
2, the concept of a leap year: Baidu Encyclopedia description-four years a leap, a century does not leap, 400 years before the leap
View Http://baike.baidu.com/view/29649.htm
3, the integration of expression
Excepting
Year can be unified writing: (?!) 0000) [0-9]{4}
The month of all years including excepting includes 1-28 days: (0[1-9]|1[0-2])-(0[1-9]|1[0-9]|2[0-8])
All years including excepting included 29 and 30th in addition to February: (0[13-9]|1[0-2)-(29|30)
All years including excepting 1, 3, 5, 7, 8, 10, December all contain 31st: (0[13578]|1[02])-31)
All other dates apart from the leap year of February 29 are: (?! 0000) [0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|1[0-9]|2[0-8]) | ( 0[13-9]|1[0-2])-(29|30) | (0[13578]|1[02])-31)
Run year
Year that can be divisible by 4 but not divisible by 100: ([0-9]{2} (0[48]|[ 2468][048]| [13579] [26])
Year that can be divisible by 400. The number divisible by 400 can certainly be divisible by 100, so the latter two must be 00: (0[48]|[ 2468][048]| [13579] [26]) 00
Together is the February 29 of all Leap years: ([0-9]{2} (0[48]|[ 2468][048]| [13579] [26]) | (0[48]| [2468] [048]| [13579] [26]) 00)-02-29)
All four rules are implemented and have no effect on each other, and together is the regular of all dates that match the DateTime range
^((?! 0000) [0-9]{4}-(0[1-9]|1[0-2])-(0[1-9]|1[0-9]|2[0-8]) | ( 0[13-9]|1[0-2])-(29|30) | (0[13578]|1[02])-31 | ([0-9]{2} (0[48]|[ 2468][048]| [13579] [26]) | (0[48]| [2468] [048]| [13579] [26]) 00)-02-29) $
Given that this regular expression is used only as validation, capturing groups are meaningless, consume resources and affect the efficiency of matching, so you can use a non-capturing group for optimization.
^(?:(?! 0000) [0-9]{4}-(?:(?: 0 [1-9]|1[0-2])-(?: 0 [1-9]|1[0-9]|2[0-8]) | (?: 0 [13-9]|1[0-2])-(?: 29|30) | (?: 0 [13578]|1[02])-31 | (?: [0-9]{2} (?: 0 [48]| [2468] [048]| [13579] [26]) | (?: 0 [48]| [2468] [048]| [13579] [26]) 00)-02-29) $
Capture/non-capture of regular expressions see: http://www.jb51.net/article/28035.htm
Finally, the updated JavaScript method
Copy Code code as follows:
function Checkdate (fname) {
var sc = $ ("#" +fname);
var s = sc.val ();
if (sc==null) {
Alert ("Element is null");
return true;
}
var reg=/^ (?:(?! 0000) [0-9]{4}-(?:(?: 0 [1-9]|1[0-2])-(?: 0 [1-9]|1[0-9]|2[0-8]) | (?: 0 [13-9]|1[0-2])-(?: 29|30) | (?: 0 [13578]|1[02])-31 | (?: [0-9]{2} (?: 0 [48]| [2468] [048]| [13579] [26]) | (?: 0 [48]| [2468] [048]| [13579] [26]) 00)-02-29 $/;
if (!s.match (reg)) {
Alert ("false");
}else{
Alert ("true"); }
}
Copy Code code as follows:
<body>
<input type= "Date" name= "TextField" id= "Text1" >
<input type= "button" value= buttons "onclick=" checkdate (' Text1 ') ">
</body>
correct regular expressions (including test code):
Copy Code code as follows:
var str = ' 2009-12-33 ';
if (Str.match (/^: 19|20) \d\d)-(0[1-9]|1[012))-(0[1-9]|[ 12][0-9]|3[01]) ($/)) {
Alert (' is Date ');
} else {
Alert (' not date ');
}
