Strings in Java : Part 4

String Methods

As we know that string class has variety of methods for String manipulation. We would be explaining the mostly used methods available in string class in detailed manner.

• String length()
• The length()  method returns the number of characters available in the string.

 Considering the following program

public class Main {

  public static void main(String[] args) {

    

    String str = "Hello World";

    

    int len = str.length();

System.out.println("The string length of '"+str+"' is: "+len);

    

 }

}

The output of the program would be 11 .

Have you noted the above length() function did calculated the white space as well now you may have a requirement where you do want the white spaces in your program . How to handle this?

public class Main {

  public static void main(String[] args) {

    

    String str = "Hello World";

    

    int len = str.replace(" ", "").length();  [Here worried about what does replace method do ? Do not be we have explained it below :D]

System.out.println("The string length of  is: "+len);

    

 }

}

The output of the program would be 10

• String Replace()
• The replace method replaces the old character/string with the new set of character or string. The function accepts 2 arguments
• Replace(old char, new char)

public class Main{  

public static void main(String args[]){  

       String s1="Hello World";  

       String replaceString=s1.replace("Hello ","Happy");//replaces all occurrences of "Hello" to "Happy"  

       System.out.println(replaceString);  

 }

}  

The output of the program would be HappyWorld