Switch Statement in Java

Last Updated: 28 May, 2022

In Java, the switch statement allows us to execute a block of statements among many alternatives options. It is similar to the Java if...else...if ladder.

The expression can be a byte, short, char, or int (primitive data types). Since Java 7, it also works with enumerated types (Enums in java), the String class, and Wrapper classes.

Syntax for writing switch statement in Java

  switch (expression) {
    case value1:
      // code
      break;
    
    case value2:
      // code
      break;
    
    ...
    ...
    
    default:
      // default statements
  }

Flowchart of Switch Statement

Some Important points for switch statements

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.
We can write any number of case statements inside a switch but It does not allow duplicate case inside a switch.
'break' keyword is an optional, if we skip break statement execution will continue on into the next case.
Switch does not allow variables it only accept a constant or a literal.
Inside the switch, the break statement is maily used to terminate a statement sequence.
Default case is an optional inside a swich statement, It is used for printing the default output value if when none of the cases is true.
default case must be appear at the end of the switch statement and break statement is also not required.

Coding Tips: If the number of cases exceeds 5, always use switch statement in your programming, otherwise if-else can be used.

Example 1 : Switch Statement implementation in Java

// Java program to demonstrate switch case
public class SwitchExample {
	public static void main(String[] args)
	{
		int number_of_day = 3;
		switch (number_of_day) {
		case 1:
			System.out.println("It is Sunday");
			break;
		case 2:
			System.out.println("It is Monday");
			break;
		case 3:
			System.out.println("It is Tuesday");
			break;
		case 4:
			System.out.println("It is Wednesday");
			break;
		case 5:
			System.out.println("It is Thursday");
			break;
		case 6:
			System.out.println("It is Friday");
			break;
		case 7:
			System.out.println("It is Saturday");
			break;
		default:
			System.out.println("Invalid Day Number, Try again.");
		}
	}
}

Output

It is Tuesday

Example 2 : Switch Statement implementation using String

Using strings in a switch expression is possible since Java SE 7. The case statement must be a string literal. Let's see the below given example.

  public class SwitchWithStringExample {
    public static void main(String[] args) {
      String courseName = "MCA";
      switch (courseName) {
      case "BCA":
        System.out.println("Bachelor of Computer Application");
        break;
      case "MCA":
        System.out.println("Master of Computer Application");
        break;
      case "DCA":
        System.out.println("Diploma in Computer Application");
        break;
      case "ADCA":
        System.out.println("Advance Diploma in Computer Application");
        break;
      default:
        System.out.println("Invalid Course Name, Try again.");
      }
    }
  }

Output

Master of Computer Application

Example 3 : Switch Statement implementation using Enums

  public class SwitchWithEnumExample {
    private static enum Colour {
      RED, GREEN, YELLOW, BLUE
    }
    
    void displayYourColour(Colour colour) {
      switch (colour) {
      case RED:
        System.out.println("Your colour is Red.");
        break;
      case GREEN:
        System.out.println("Your colour is Green.");
        break;
      case YELLOW:
        System.out.println("Your colour is Yellow.");
        break;
      case BLUE:
        System.out.println("Your colour is Blue.");
        break;
      default:
        System.out.println("Please input valid colour name, try again.");
      }
    }
    
    public static void main(String args[]) {
      SwitchWithEnumExample obj = new SwitchWithEnumExample();
      obj.displayYourColour(Colour.GREEN);
    }
  }

Output

Your colour is Green.

Example 4 : Switch Statement without break Keyword using Wrapper Class

  public class SwitchWithoutBreakExample {
    public static void main(String[] args) {
      Integer number_of_day = 4;
      switch (number_of_day) {
      case 1:
      case 2:
      case 3:
      case 4:
      case 5:
        System.out.println("It's a Working Day");
        break;
      case 6:
      case 7:
        System.out.println("It's a Rest Day");
        break;
      default:
        System.out.println("Invalid Day Number, Try again.");
      }
    }
  }

Output

It's a Working Day

Example 5 : Nested Switch Statements implementation in Java

Java allows to write nested switch statements that means one switch statement can contain another switch statement just like nested if-else statement. Let's see the program and try to understand how to implement nested switch statements.

  public class NestedSwitchStatement {
    public static void main(String[] args) {
      String className = "Nursery";
      char sectionName = 'B';
  
      switch (className) {
      case "Nursery":
        switch (sectionName) {
        case 'A':
          System.out.println("Nursery - 'A', Total Students: 45");
          break;
        case 'B':
          System.out.println("Nursery - 'B', Total Students: 38");
          break;
        default:
          System.out.println("Please enter valid section.");
        }
        break;
      case "LKG":
        switch (sectionName) {
        case 'A':
          System.out.println("LKG - 'A', Total Students: 44");
          break;
        case 'B':
          System.out.println("LKG - 'B', Total Students: 54");
          break;
        default:
          System.out.println("Please enter valid section.");
        }
        break;
      default:
        System.out.println("Please enter valid class name.");
      }
    }
  }

Output

Nursery - 'B', Total Students: 38

Switch Statement in Java

Switch Statement - Interview Questions and Answers

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