Question

I’m trying to extract the time from the following strings using regex

Free concert at 8 pm over there
Free concert at 8pm over there
Free concert at 8:30 pm over there
Free concert at 8:30pm over there

Does anybody know how to do this using Regex in java?

I’ve tried the following (1[012]|[1-9]):[0-5]0-9?(?i)(am|pm) but I dont think it allows for words before or after.

Thanks!

Answer 1

Try this one: (?i)at (.+?) over

Example:

String str = "Free concert at 8 pm over there"
        + "Free concert at 8pm over there"
        + "Free concert at 8:30 pm over there"
        + "Free concert at 8:30pm over there";

Pattern p = Pattern.compile("(?i)at (.+?) over");
Matcher m = p.matcher(str);

while( m.find() )
{
    System.out.println(m.group(1));
}

Output:

8 pm
8pm
8:30 pm
8:30pm

Another one (only time, without at / over or any other word):

(?i)[0-9]{1,2}:??[0-9]{0,2}\\s??(?:am|pm)

But there you dont need group(1) (you can take group(0) or simply group())!

Example:

String str = "Free concert at 8 pm over there"
        + "Free concert at 8pm over there"
        + "Free concert at 8:30 pm over there"
        + "Free concert at 8:30pm over there";

Pattern p = Pattern.compile("(?i)[0-9]{1,2}:??[0-9]{0,2}\\s??(?:am|pm)");
Matcher m = p.matcher(str);

while( m.find() )
{
    System.out.println(m.group());
}