Replace a Character in a String

 

public class strrep
{
    public static void main(String args[])
    {
        char oldchar='A';
        char newchar='Z';
        String str="AAA";

        System.out.println("Old String : "+str);

        str=str.replace(oldchar,newchar);

        System.out.println("New String :"+str);
    }
}