Java String replaceAll() method

Java String replaceAll() method returns a String replacing all the sequence of characters matching regular expression i.e regex and replacement string.

Syntax:

public String replaceAll(String regex, String replacement)

Parameters:

regex : regular expression

replacement : replacement sequence of characters

Returns:

a new String i.e. replaced String

Java String replaceAll() example 1: replace character

    public class JavaStringReplaceAllEx1
    { 
    public static void main(String args[])
    { 
    String s1="W3lcom3 to the TutorialsAndExampl3"; 
    String replaceString=s1.replaceAll("3","e");
    System.out.println(replaceString); 
       }   
    }

Output:

Welcome to the TutorialsAndExample

Java String replaceAll() example 2: replace word

public class JavaStringReplaceAllEx2
    { 
             public static void main(String args[])
             { 
    String s1="Welcome to rock TutorialAndExample"; 
    String replaceString=s1.replaceAll("rock","the");//replaces all occurrences of "rock" to "the" 
    System.out.println(replaceString); 
              }     
     }

Output:

Welcome to the TutorialAndExample

Java String replaceAll() example 3

public class JavaStringReplaceEx3 { 
    public static void main(String[] args) { 
        String str = "JABA IS THE BEST"; 
        String rs = str.replaceAll("JABA","JAVA");
        System.out.println(rs);
        String str1 = rs.concat(" PROGRAMMING LANGUAGE");
        System.out.println(str1);
        String rs2 = str1.replaceAll("THE BEST","A OBJECT ORIENTED");
        System.out.println(rs2);
    } 
}

Output:

JAVA IS THE BEST
JAVA IS THE BEST PROGRAMMING LANGUAGE
JAVA IS A OBJECT ORIENTED PROGRAMMING LANGUAGE

Java String replaceAll() example 4: remove white spaces

    public class JavaStringReplaceAllEx4
          { 
                 public static void main(String args[])
                 { 
                 String s1="tutorial and example  .com"; 
                 String replaceString=s1.replaceAll("\\s",""); 
                System.out.println(replaceString); 
          }     
       }

Output:

tutorialandexample.com