how to replace + string java code example

Example 1: string replace java

public static void main(String args[]){  
String s1="my name is khan my name is java";  
String replaceString=s1.replace("is","was");//replaces all occurrences of "is" to "was"  
System.out.println(replaceString);  
}}

Example 2: Java string replace

String a = "Cool";
a = a.replace("o","yy");