switch case in java
Introduction
Instead of using if-else if ladder we can use switch case statement. The switch-case statement use when multiple
option available. A switch-case work with primitive data types and it also work
with enumerated types.
- The case use as literal or constant.
- Case must be unique
- With JDK 7 and after word, String literal/constant is also use to control a switch statement.
- The value passes from switch can be have any integer value after case keyword.
- And can take any order of value.
- It is mainly use in menu driven program
The syntax of Switch case statement
Switch (expression) {
case 1:
// code block
break;
case 2:
// code block
break;
case 3:
// code block
break;
case 4:
// code block
break;
default:
// code block
}
Switch-case statement generally use with break statement as it not pass
boolean (true or false) value like in if else statement. In switch-case,
expression pass, say int value 1 and case 1: is executed and then case 2: block
execute till remaining case. And if no case will match then default block is
use.
import java.util.*;
public class WeekDay
{
public static void
main(String args[])
{
Scanner sc=new Scanner
(System.in);
int day;
System.out.println
("Enter 1-7 :");
day=sc.nextInt();
switch(day)
{
case 1:
System.out.println
("Sunday");
break;
case 2:
System.out.println
("Monday");
break;
case 3:
System.out.println
("Tuesday");
break;
case 4:
System.out.println
("Wednesday");
break;
case 5:
System.out.println
("Thursday");
break;
case 6:
System.out.println
("Friday");
break;
case 7:
System.out.println
("Saturday");
break;
default:
System.out.println
("Wrong Choice");
}
}
}
In the above program user enter 1 to 7 as day. If user press 1 it will
print Sunday, if user press 2 it will print Monday and so on. Here when user
press 1-7 as an input it passes as parameter from switch statement and match
with the case, and if found the exact match it will print the match block and
break from the switch case block.
Look into another example which is a menu driven program.
public class MenuCalculator
{
// main method
public static void
main(String args[])
{
// menu method
int num1, num2, add, sub,
mul, div, choice;
Scanner sc=new
Scanner(System.in);
// menu list
System.out.println("Press 1 For Addition");
System.out.println("Press 2 For Substraction");
System.out.println("Press 3 For Multiplication");
System.out.println("Press 4 For Division");
System.out.println("Press 5 For Exit\n\n");
System.out.println("Enter Your Choice");
choice = sc.nextInt();
switch(choice)
{
case 1:
System.out.println("Enter two Numbers:");
num1 = sc.nextInt();
num2 = sc.nextInt();
add = num1 +
num2; // addition
System.out.println("Sum="
+ add);
break;
case 2:
System.out.println("Enter two Numbers:");
num1 = sc.nextInt();
num2 = sc.nextInt();
sub= num1 -
num2; // Substraction
System.out.println("Subs="
+ sub);
break;
case 3:
System.out.println("Enter two Numbers:");
num1 = sc.nextInt();
num2 = sc.nextInt();
mul = num1 *
num2; // multiplication
System.out.println("Mult="
+ mul);
break;
case 4:
System.out.println("Enter two Numbers:");
num1 = sc.nextInt();
num2 = sc.nextInt();
div = num1 /
num2; // division
System.out.println("Div="
+ div);
break;
case 5:
System.out.println("Thank you for using me");
System.exit(0); // exit from program
default:
System.out.println("Wrong Choice, please press(1-5)");
}
}
}
Conclusion in java switch
So switch case statement in java is used to transfer control to a specified
block of code, which is based on the value provided by the user. The value
provided by the user can based on int, String, enums, char etc.
More Java program
