An example of Regular Expression search and replace program

This Java tip illustrates an example of Quintessential Regular Expression search and replace program. This program finds all matches to a regular expression pattern and replaces them with another string.

import java.util.regex.*;

public class BasicReplace {

public static void main(String[] args) {

CharSequence inputStr = "p q r p q r ";
String patternStr = "q";
String replacementStr = "s";

// Compile regular expression
Pattern pattern = Pattern.compile(patternStr);

// Replace all occurrences of pattern in input
Matcher matcher = pattern.matcher(inputStr);
String output = matcher.replaceAll(replacementStr);
// p s r p s r
}
}