We have been doing decision making by using if statement. The switch statement is also used for decision making.

To understand the switch statement, let's consider a problem. We will first solve this problem by using if and then we will solve this problem by using switch statement. Let us consider a program that will input a number from 1-7 and then display the day of week that corresponds to the number. The correspondence is as follows:
1. Monday
2. Teuesday
3. Wednesday
4. Thursday
5. Friday
6. Saturday
7. Sunday

Solution for this problem by using if

Now let's see the syntax for switch statement:
switch (variable)
{
case value1 :
/*This will be executed if the value of variable is equal to the value1*/
break;
case value2 :
/*This will be executed if the value of variable is equal to value2*/
default :
/*This will be executed if the value of variable is not equal to any of the above values*/
}

*You can use as many case statements as you want
**It is not necessary to add the default statement
***If you do not add the break; statement, all the below statements will also be executed

Now let's solve the above problem using switch:
package lesson.pkg13;
import java.util.Scanner;
public class Lesson13 {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int i=in.nextInt();
        switch (i) {
            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("Wromg input");
        }
    }
}


*Try to remove break; to see what happens

Practice Corner:

  • Write a program to input the month number and display the name of the month on the screen.