Question

I’m doing a project which requires numerical pattern matching.
For example i want to know whether Value = 1331 is a part of 680+651 = 1331 or not, i.e. i want to match 1331 with 680+651 = 1331 or any other given string.
I’m trying pattern matching in java for the first time and i could not succeed. Below is my code snippet.

String REGEX1=s1;   //s1 is '1331' 
pattern = Pattern.compile(REGEX1);
matcher = pattern.matcher(line_out);   //line_out is for ex. 680+651 = 1331
System.out.println("lookingAt(): "+matcher.lookingAt());
System.out.println("matches(): "+matcher.matches());    

It is returning false all the times.
Pls help me.

Answer 1

The matches method requires a perfect, full exact match. Since there is more text in 680+651=1331 than what is matched by the regex 1331, matches returns false.

As I pointed out in Brian’s post, you need to be careful in your regex to ensure that a regex of 1331 does not match the number 213312 unless that is what you want.