12小时时间戳的正则表达式以及对时间端点的支持

Question

一直试图让这个正则表达式正常工作，但似乎无法做到。

我需要的正则表达式基本回暖的时候，这些组合：

12am 
12:30am 
12am - 12pm 
12:30am - 1:30am 
12:30 - 1:30am 
12 - 1:30am 

如果我加入？在我的（[a | p] m）部分后面，正则表达式将匹配我不想要的数字。

这里是我的正则表达式代码：

(?:(1[012]|[1-9]):([0-5][0-9])|(1[012]|[1-9])) ?([a|p]m)(?:\s-\s(?:(1[012]|[1-9]):([0-5][0-9])|(1[012]|[1-9])) ?([a|p]m))? 

任何帮助表示赞赏，谢谢。

Answer 1

该做的工作：

((?:1[0-2]|\d)(?:\:[0-5]\d)?(?:[ap]m)?)[\s-]+((?:1[0-2]|\d)(?:\:[0-5]\d)?(?:[ap]m)?) 

Live Demo。

解释（第二组是相同的第一个）：

1st Capturing group ((?:1[0-2]|\d)(?:\:[0-5]\d)?(?:[ap]m)) 

(?:1[0-2]|\d) Non-capturing group 
    1st Alternative: 1[0-2] 
     1 matches the character 1 literally 
     [0-2] match a single character present in the list below 
      0-2 a single character in the range between 0 and 2 
    2nd Alternative: \d 
     \d match a digit [0-9] 
(?:\:[0-5]\d)? Non-capturing group 
    Quantifier: ? Between zero and one time, as many times as possible, giving back as needed [greedy] 
    \: matches the character : literally 
    [0-5] match a single character present in the list below 
     0-5 a single character in the range between 0 and 5 
    \d match a digit [0-9] 
(?:[ap]m) Non-capturing group 
    [ap] match a single character present in the list below 
     ap a single character in the list ap literally (case insensitive) 
    m matches the character m literally (case insensitive) 

[\s-]+ match a single character present in the list below 

Quantifier: + Between one and unlimited times, as many times as possible, giving back as needed [greedy] 
\s match any white space character [\r\n\t\f ] 
- the literal character -