Switch-case

A switch is a multiple-choice decision-making statement. In this statement, there are various types of cases. If any case matches the input (expression), then that particular case will execute.

It contains multiple case blocks, each representing a condition.
If a case matches the expression, its code block executes.
The break keyword is used to stop further execution.
The default block runs when no case matches.

Syntax:

switch(expression){    
case A:    
 //code block;    
 break; 
  //optional  
  case B:    
 //code block;    
 break;  
 default:  
    // code block
  }

Example:

package quipohouse;
public class SwitchCase {
	public static void main(String[] args) {
		int day = 3;
		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;
		}
	}
}

Output:

Wednesday

Use of break in switch case:

The break keyword breaks the statement execution, If we do not add the break keyword in the switch case then all onward cases will execute till the break keyword is encountered.

Example-1:

package quipohouse;
public class SwitchCase {
	public static void main(String[] args) {
		int day = 1;
		switch (day) {
		case 1:
			System.out.println("Monday");
		case 2:
			System.out.println("Tuesday");
		case 3:
			System.out.println("Wednesday");
		case 4:
			System.out.println("Thursday");
		case 5:
			System.out.println("Friday");
		case 6:
			System.out.println("Saturday");
		case 7:
			System.out.println("Sunday");
		}
	}
}

Output:

Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday

Example-2:

package quipohouse;
public class SwitchCase {
	public static void main(String[] args) {
		int day = 1;
		switch (day) {
		case 1:
			System.out.println("Monday");
		case 2:
			System.out.println("Tuesday");
		case 3:
			System.out.println("Wednesday");
		case 4:
			System.out.println("Thursday");
			break;
		case 5:
			System.out.println("Friday");
		case 6:
			System.out.println("Saturday");
			break;
		case 7:
			System.out.println("Sunday");
		}
	}
}

Output:

Monday
Tuesday
Wednesday
Thursday

Use of default in a switch case:

If the expression does not match any of the conditions then the default block will execute.

Example:

package quipohouse;
public class SwitchCase {
	public static void main(String[] args) {
		int day =10;
		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("Enter valid input!!");
		}
	}
}

Output:

Enter valid input!!