How to replace whole word with Word Boundaries in Java?

If you want to replace the whole word with the word boundaries in a string. For this, we use "\b" regular expression token which is called a word boundary. It usually matches at the start or the end of a word.

How to replace a word in a sentence in java

You just need to place the word between word boundaries

Example:

package com.legendblogs.test;
public class TestApps {
    /*
      *@param args
     */
    public static void main(String[] args){
        String s = "A man is an Ironman like manpower";
        //It will replace if the first character is a word character or not
        String d = s.replaceAll("\\bman", "tony");
        System.out.println(d);
        //It will replace if  if the last character is a word character or not
        String b = s.replaceAll("man\\b", "tony");
        System.out.println(b);
        //It will replace whole word only
        String c = s.replaceAll("\\bman\\b", "tony");
        System.out.println(c);
   }
}

Output:

A tony is an Ironman like tonypower
A tony is an Irontony like manpower
A tony is an Ironman like manpower