Java Control Statements - Switch Statements

April 16, 2018 Oclemy Java Control Statements 1 minute, 23 seconds

A switch statement executes statements based on the value of a variable or an expression.

Switch statements simply working with several conditions. Normally an if statement makes selctions based on a single true or false condition.

Switch statements have the following syntax:

        switch (key) {
            case value1:
                break;
            case value2:
                break;
            case value3:
                break;
            default:
                break;
        }

How Switch Statement works

Here's how switch statements work and the rules to take into account:

  1. The switch expression must yield a value of

    • int
    • byte
    • short
    • char
    • String Furthermore it alwyas needs to be wrapped in a parenthesis.
  2. The values in the case statement must be of the same data type. And they need to be constant expressions, meaning they must not contain variables like value1+value2.

  3. When a match is made in a case statement, the statements defined in the body of that case statement are executed until a break statement is encountered. This is referred to a s a fall through behavior.

  4. The default case is optional. It can be used to perform actions when none of the specified cases match the switch expression.

  5. The keyword break is optional.

Example

import java.util.Scanner;

public class MrSwitch {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        System.out.print("Enter Your Day Code: ");
        int day = input.nextInt();

        switch (day) {
            case 1:
                System.out.println("Monday");
                break;
            case 2:
                System.out.println("Tuesday");
                break;
            case 3:
                System.out.println("Wednesday");
                break;
            case 4:
                System.out.println("Thursday");
                break;
            case 5:
                System.out.println("Friday");
                break;
            case 6:
                System.out.println("Saturday");
                break;
            case 7:
                System.out.println("Sunday");
                break;
            default:
                System.out.println("Date out of Range");
                break;
        }

    }

}

Result

Enter Your Day Code: 4
Thursday

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