java - How can I count the number of a special character in a regular expression? -


well, i'm beginner in working regular expressions , wanna design program language contains of , b ( mean want accept words using , b.) starts counting number of a, , b in expression enter. don't know methods useful in case...

you cannot count occurances of character x in string regular expressions. can validate fixed number n of x present. make familiar regular, context free , context sensitive grammars.

you should use java.util.scanner, tokenize input , count it.


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