Best Use Of Switch Statement In Java8

Table of Contents

How to Use Switch Statement in Java

Switch Statement in Java

 

 

switch statement in Java allows a variable to be tested for equality against a list of values. Each value is called a case, and the variable being switched on is checked for each case.

Syntax

The syntax of enhanced for loop is −

 

 

 

switch(expression) {
   case value :
      // Statements
      break; // optional
   
   case value :
      // Statements
      break; // optional
   
   // You can have any number of case statements.
   default : // Optional
      // Statements
}

The following rules apply to a switch statement in Java

  • The variable used in a switch statement in Java can only be integers, convertible integers (byte, short, char), strings and enums.
  • The value for a case must be the same data type as the variable in the switch and it must be a constant or a literal.
  • When the variable being switched on is equal to a case, the statements following that case will execute until a break statement is reached.
  • You can have any number of case statements within a switch. Each case is followed by the value to be compared to and a colon.
  • When a break statement is reached, the switch terminates, and the flow of control jumps to the next line following the switch statement.
  • Not every case needs to contain a break. If no break appears, the flow of control will fall through to subsequent cases until a break is reached.
  • switch statement can have an optional default case, which must appear at the end of the switch. The default case can be used for performing a task when none of the cases is true. No break is needed in the default case.

Flow Diagram

Switch Statement in Java

Example of Switch statement in Java

public class Test {

   public static void main(String args[]) {
      // char grade = args[0].charAt(0);
      char grade = 'C';

      switch(grade) {
         case 'A' :
            System.out.println("Excellent!"); 
            break;
         case 'B' :
         case 'C' :
            System.out.println("Well done");
            break;
         case 'D' :
            System.out.println("You passed");
         case 'F' :
            System.out.println("Better try again");
            break;
         default :
            System.out.println("Invalid grade");
      }
      System.out.println("Your grade is " + grade);
   }
}

Compile and run the above program using various command line arguments. This will produce the following result −

Output

Well done
Your grade is C