String replace method

With this example we are going to demonstrate how to use the replace method of String class. The String class represents character strings. All string literals in Java programs, such as "abc", are implemented as instances of this class. In short, to replace a String you should:

• Create a new String.
• Use replace(char oldChar, char newChar) API method. This method returns a new string resulting from replacing all occurrences of oldChar in this string with newChar.
• Use replaceFirst(String regex, String replacement) API method. It replaces the first substring of this string that matches the given regular expression with the given replacement.
• Use replaceAll(String regex, String replacement) API method. It replaces each substring of this string that matches the given regular expression with the given replacement.

Let’s take a look at the code snippet that follows:

package com.javacodegeeks.snippets.core;

public class StringReplaceMethod {
	
	public static void main(String[] args) {
		
		String s = "Java Code Geeks - Java Examples";
		
		// replace all occurrences of given character with new one
		System.out.println(s.replace('e','i'));
		 
		// replace only first occurrence of given string
		System.out.println(s.replaceFirst("Ja", "Je"));
		 
		// replace all occurrence of given string
		System.out.println(s.replaceAll("Ja", "Je") );
		
	}

}

Output:

Java Codi Giiks - Java Examplis
Jeva Code Geeks - Java Examples
Jeva Code Geeks - Jeva Examples

 
This was an example of how to use the replace method of String class in Java.