我需要一个与日期和可选时间匹配的正则表达式模式。
日期应为m/d/yyyy格式的有效美国日期。时间应为h:mm:ss am/pm或24小时hh:mm:ss。
匹配：2011年9月1日| 2011年9月1日上午10:00 | 9/1/2011 10:00 AM | 9/1/2011 10:00:00
这个模式将在Ruby on Rails项目中使用，因此它应该是可以通过Ruby使用的格式。请参阅http://rubular.com/进行测试。
这是我现有的日期模式（可能是过度杀戮）：
DATE_PATTERN = /^((((0[13578])|([13578])|(1[02]))[\/](([1-9])|([0-2][0-9])|(3[01])))|(((0[469])|([469])|(11))[\/](([1-9])|([0-2][0-9])|(30)))|((2|02)[\/](([1-9])|([0-2][0-9]))))[\/]\d{4}$|^\d{4}/
答案 0 :(得分：8)
正则表达式对于这种工作来说太可怕了。如果您使用的是Ruby，我建议使用DateTime.strptime来解析数据并检查其有效性：
def validate_date(date_str)
valid_formats = ["%m/%d/%Y", "%m/%d/%Y %I:%M %P"]
#see http://www.ruby-doc.org/core-1.9.3/Time.html#method-i-strftime for more
valid_formats.each do |format|
valid = Time.strptime(date_str, format) rescue false
return true if valid
end
return false
end
答案 1 :(得分：2)
嗯，这就是我最终的结果;使用更严格的军事时间：
DATE_TIME_FORMAT = /^([0,1]?\d{1})\/([0-2]?\d{1}|[3][0,1]{1})\/([1]{1}[9]{1}[9]{1}\d{1}|[2-9]{1}\d{3})\s([0]?\d|1\d|2[0-3]):([0-5]\d):([0-5]\d)$/
比赛：1/19/2011 23:59:59
捕获：
- 1
- 19
- 2011
- 23
- 59
- 59
答案 2 :(得分：1)
if subject =~ /\A(?:0?[1-9]|1[012])\/(?:0?[1-9]|[12]\d|3[01])\/(?:\d{4})(?:\s+(?:(?:[01]?\d|2[0-3]):(?:[0-5]\d)|(?:0?\d|1[0-2]):(?:[0-5]\d)\s+[ap]m))?\s*\Z/i
# Successful match
工作原理：
"
^ # Assert position at the beginning of the string
(?: # Match the regular expression below
# Match either the regular expression below (attempting the next alternative only if this one fails)
0 # Match the character “0” literally
? # Between zero and one times, as many times as possible, giving back as needed (greedy)
[1-9] # Match a single character in the range between “1” and “9”
| # Or match regular expression number 2 below (the entire group fails if this one fails to match)
1 # Match the character “1” literally
[012] # Match a single character present in the list “012”
)
/ # Match the character “/” literally
(?: # Match the regular expression below
# Match either the regular expression below (attempting the next alternative only if this one fails)
0 # Match the character “0” literally
? # Between zero and one times, as many times as possible, giving back as needed (greedy)
[1-9] # Match a single character in the range between “1” and “9”
| # Or match regular expression number 2 below (attempting the next alternative only if this one fails)
[12] # Match a single character present in the list “12”
\d # Match a single digit 0..9
| # Or match regular expression number 3 below (the entire group fails if this one fails to match)
3 # Match the character “3” literally
[01] # Match a single character present in the list “01”
)
/ # Match the character “/” literally
(?: # Match the regular expression below
\d # Match a single digit 0..9
{4} # Exactly 4 times
)
(?: # Match the regular expression below
\s # Match a single character that is a “whitespace character” (spaces, tabs, line breaks, etc.)
+ # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
(?: # Match the regular expression below
# Match either the regular expression below (attempting the next alternative only if this one fails)
(?: # Match the regular expression below
# Match either the regular expression below (attempting the next alternative only if this one fails)
[01] # Match a single character present in the list “01”
? # Between zero and one times, as many times as possible, giving back as needed (greedy)
\d # Match a single digit 0..9
| # Or match regular expression number 2 below (the entire group fails if this one fails to match)
2 # Match the character “2” literally
[0-3] # Match a single character in the range between “0” and “3”
)
: # Match the character “:” literally
(?: # Match the regular expression below
[0-5] # Match a single character in the range between “0” and “5”
\d # Match a single digit 0..9
)
| # Or match regular expression number 2 below (the entire group fails if this one fails to match)
(?: # Match the regular expression below
# Match either the regular expression below (attempting the next alternative only if this one fails)
0 # Match the character “0” literally
? # Between zero and one times, as many times as possible, giving back as needed (greedy)
\d # Match a single digit 0..9
| # Or match regular expression number 2 below (the entire group fails if this one fails to match)
1 # Match the character “1” literally
[0-2] # Match a single character in the range between “0” and “2”
)
: # Match the character “:” literally
(?: # Match the regular expression below
[0-5] # Match a single character in the range between “0” and “5”
\d # Match a single digit 0..9
)
\s # Match a single character that is a “whitespace character” (spaces, tabs, line breaks, etc.)
+ # Between one and unlimited times, as many times as possible, giving back as needed (greedy)
[ap] # Match a single character present in the list “ap”
m # Match the character “m” literally
)
)? # Between zero and one times, as many times as possible, giving back as needed (greedy)
\s # Match a single character that is a “whitespace character” (spaces, tabs, line breaks, etc.)
* # Between zero and unlimited times, as many times as possible, giving back as needed (greedy)
$ # Assert position at the end of the string (or before the line break at the end of the string, if any)
"
记住，不是你的勺子，而是你！
答案 3 :(得分：0)
这就是我提出的似乎有效的方法：
regex = /^1?\d{1}\/[123]?\d{1}\/\d{4}(\s[12]?\d:[0-5]\d(:[0-5]\d)?(\s[ap]m)?)?$/