JAVA EE: How to replace the values in the text with new values using replace methods

Monday 25 December 2017

How to replace the values in the text with new values using replace methods | Regex in java

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https://www.youtube.com/watch?v=GWSdx6ShkGs&list=UUhwKlOVR041tngjerWxVccw

RegexDemo.java

import java.util.regex.Matcher;

import java.util.regex.Pattern;

/**
 * 
 * replaceAll() and replaceFirst():
 * 
 * The Matcher replaceAll() and replaceFirst() methods can be used to
 * replace parts of the string the Matcher is searching through.
 *
 */

public class RegexDemo

{

    public static void main(String[] args)

    {

        String text = "John peter about this, and John Doe writes about that,"

                + " and John Wayne writes about everything.";

        String regex = "(John)";

        Pattern pattern = Pattern.compile(regex);

        Matcher matcher = pattern.matcher(text);

        /*
         * The replaceAll() method replaces all matches of the regular
         * expression.
         */

        String replaceAll = matcher.replaceAll("Steve");

        System.out.println("replaceAll   = " + replaceAll);

        /*
         * The replaceFirst() only replaces the first match.
         */

        String replaceFirst = matcher.replaceFirst("Steve");

        System.out.println("replaceFirst = " + replaceFirst);

    }

}

Output

replaceAll   = Steve peter about this, and Steve Doe writes about that, and Steve Wayne writes about everything.

replaceFirst = Steve peter about this, and John Doe writes about that, and John Wayne writes about everything.