How can I understand if a regex partially matches its subject?
I tried this:
Pattern.compile("^\\d").matcher("01L").hitEnd()
and this:
Pattern.compile("^\\d").matcher("01L").matches()
and they are both false, I want to test if the string starts with a digit.
Use matcher.find() method:
boolean valid = Pattern.compile("^\\d").matcher("01L").find(); //true
PS: If you're using find in a loop or multiple times it is better to do:
Pattern p = Pattern.compile("^\\d"); // outside loop
boolean valid = p.matcher("01L").find(); // repeat calls
You are getting:
matches attempts to match the entire input against the pattern hence it returns false.hitEnd returns true if the end of input was hit by the search engine in the last match operation performed by this matcher and since it didn't you get false