switch statement in java

Switch:

• A conditional control statement used to execute a block based on value of expression.
• Expression can be byte, short, char and int primitive types.
• It can work with Strings and Wrapper objects also.

Syntax:

switch(expression)
{
	case value1 :
		statements;
		break; 
	case value2 :
		Statements;
		break;
	default : 
		Statements
}

Code program:

import java.util.Scanner ;
class SwitchStatement 
{
	public static void main(String[] args) 
	{
		Scanner sc = new Scanner(System.in);
		System.out.print("Enter a character : ");
		char ch = sc.nextLine().charAt(0);
		switch(ch)
		{
			case 'r'	:	System.out.println("Red");
						break;
			case 'g'	:	System.out.println("Green");
						break;
			case 'b'	:	System.out.println("Blue");
						break;
			default	:	System.out.println("Weird color");
						break;
		}
	}
}

Code Program:

class SwitchStatement 
{
	public static void main(String[] args) 
	{
		int x=1 ;
		switch(x)
		{
			case 0		:	x++ ;
			case 1		:	x+=3 ;
			case 2		:	x=2 ;
			default	:	--x ;
		}
		System.out.println("X value : "+x);
	}
}

Menu Driven Program:

import java.util.Scanner;
public class Test 
{
	public static void main(String[] args) 
	{
		Scanner scan = new Scanner(System.in);
		int ch, a=0, b=0;
		while(true)
		{
			System.out.println("Arithmetic operations : ");
			System.out.println("1. Add");
			System.out.println("2. Subtract");
			System.out.println("3. Multiply");
			System.out.println("4. Exit");
		
			System.out.print("Enter your choice : ");
			ch = scan.nextInt();

			if(ch>=1 && ch<=3)
			{
				System.out.println("Enter 2 numbers : ");
				a = scan.nextInt();
				b = scan.nextInt();
			}

			switch(ch)
			{
				case 1	:	Calc.add(a, b);
								break;

				case 2	:	Calc.subtract(a, b);
								break;

				case 3	:	Calc.multiply(a,b);
								break;

				case 4	:	System.exit(0);
				default:	System.out.println("Invalid choice");
			}
		}
	}
}
class Calc
{
	static void add(int a, int b){
		System.out.println("Add result : " + (a+b));
	}
	static void subtract(int a, int b){
		System.out.println("Subtract result : " + (a-b));
	}
	static void multiply(int a, int b){
		System.out.println("Multiply result : " + (a*b));
	}
}