Java Regular Expression wildcard greedy behavior

Introduction

The following code uses a wildcard to create a pattern.

It will match any sequence that begins with e and ends with d.

To do this, it uses the dot wildcard character along with the + quantifier. 


// Use wild card and quantifier. 
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class Main {
  public static void main(String args[]) {
    Pattern pat = Pattern.compile("e.+d");
    Matcher mat = pat.matcher("extend cup end table");

    while (mat.find())
      System.out.println("Match: " + mat.group());
  }/* w  ww  . j a  v  a2 s .co m*/
}

Only one match is found, and it is the longest sequence that begins with e and ends with d.

The longer sequence is found by default by find().

By default find() matches the longest sequence that fits the pattern.

This is called greedy behavior.




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