Switch-case statements:
These are a substitute for long if statements that compare a variable to several integral values
- The switch statement is a multiway branch statement. It provides an easy way to dispatch execution to different parts of code based on the value of the expression.
- Switch is a control statement that allows a value to change control of execution
Points to remember while using Switch Case
- The expression used in a switch statement must have an integral or character type, or be of a class type in which the class has a single conversion function to an integral or character type.
- There can be any number of case statements within a switch. Each case is followed by the value to be compared to and after that a colon.
- When the variable being switched on is equal to a case, the statements following that case will execute until a break statement is reached.
- When a break statement is reached, the switch terminates, and the flow of control jumps to the next line following the switch statement.
- Not every case needs to contain a break. If no break appears, the flow of control will fall through to subsequent cases until a break is reached i.e. all the case statements will get executed as soon as compiler finds a comparison to be true.
- A switch statement can have an optional default case, which must appear at the end of the switch. The default case can be used for performing a task when none of the cases is true. No break is needed in the default case.
Syntax:
switch (n) { case 1: // code to be executed if n = 1; break; case 2: // code to be executed if n = 2; break; default: // code to be executed if // n doesn't match any cases }
Nested-Switch Statement:
Nested-Switch statements refers to Switch statements inside of another Switch Statements.
Syntax:
switch(n) { // code to be executed if n = 1; case 1: // Nested switch switch(num) { // code to be executed if num = 10 case 10: statement 1; break; // code to be executed if num = 20 case 20: statement 2; break; // code to be executed if num = 30 case 30: statement 3; break; // code to be executed if num // doesn't match any cases default: } break; // code to be executed if n = 2; case 2: statement 2; break; // code to be executed if n = 3; case 3: statement 3; break; // code to be executed if n doesn't match any cases default: }
Example:
C
// Following is a simple program to demonstrate // syntax of Nested Switch Statements. #include <stdio.h> int main()
{ int x = 1, y = 2;
// Outer Switch
switch (x) {
// If x == 1
case 1:
// Nested Switch
switch (y) {
// If y == 2
case 2:
printf ( "Choice is 2");
break ;
// If y == 3
case 3:
printf ( "Choice is 3");
break ;
}
break ;
// If x == 4
case 4:
printf ( "Choice is 4");
break ;
// If x == 5
case 5:
printf ( "Choice is 5");
break ;
default :
printf ( "Choice is other than 1, 2 3, 4, or 5");
}
return 0;
} |
C++
// Following is a simple program to demonstrate // syntax of Nested Switch Statements. #include <iostream> using namespace std;
int main()
{ int x = 1, y = 2;
// Outer Switch
switch (x) {
// If x == 1
case 1:
// Nested Switch
switch (y) {
// If y == 2
case 2:
cout << "Choice is 2" ;
break ;
// If y == 3
case 3:
cout << "Choice is 3" ;
break ;
}
break ;
// If x == 4
case 4:
cout << "Choice is 4" ;
break ;
// If x == 5
case 5:
cout << "Choice is 5" ;
break ;
default :
cout << "Choice is other than 1, 2 3, 4, or 5" ;
}
return 0;
} // This code is contributed by Shubham Singh |
Java
// Following is a simple program to demonstrate // syntax of Nested Switch Statements. import java.io.*;
class GFG {
public static void main (String[] args)
{
int x = 1 , y = 2 ;
// Outer Switch
switch (x) {
// If x == 1
case 1 :
// Nested Switch
switch (y) {
// If y == 2
case 2 :
System.out.println( "Choice is 2" );
break ;
// If y == 3
case 3 :
System.out.println( "Choice is 3" );
break ;
}
break ;
// If x == 4
case 4 :
System.out.println( "Choice is 4" );
break ;
// If x == 5
case 5 :
System.out.println( "Choice is 5" );
break ;
default :
System.out.println( "Choice is other than 1, 2 3, 4, or 5" );
}
}
} // This code is contributed by Shubham Singh |
Python3
# Following is a simple program to demonstrate # syntax of Nested Switch Statements. x = 1
y = 2
# Outer Switch def switch_x(x):
switcher = {
1 : switch_y(y),
4 : "Choice is 4" ,
5 : "Choice is 5" ,
}
return switcher.get(x, "Choice is other than 1, 2 3, 4, or 5" )
def switch_y(y):
switcher = {
2 : "Choice is 2" ,
3 : "Choice is 3" ,
}
return switcher.get(y, "")
print (switch_x(x))
# This code is contributed by Shubham Singh |
C#
// Following is a simple program to demonstrate // syntax of Nested Switch Statements. using System;
public class GFG{
static public void Main ()
{
int x = 1, y = 2;
// Outer Switch
switch (x) {
// If x == 1
case 1:
// Nested Switch
switch (y) {
// If y == 2
case 2:
Console.WriteLine( "Choice is 2" );
break ;
// If y == 3
case 3:
Console.WriteLine( "Choice is 3" );
break ;
}
break ;
// If x == 4
case 4:
Console.WriteLine( "Choice is 4" );
break ;
// If x == 5
case 5:
Console.WriteLine( "Choice is 5" );
break ;
default :
Console.WriteLine( "Choice is other than 1, 2 3, 4, or 5" );
}
}
} // This code is contributed by Shubham Singh |
Javascript
<script> // Following is a simple program to demonstrate // syntax of Nested Switch Statements. var x = 1, y = 2;
// Outer Switch switch (x) {
// If x == 1
case 1:
// Nested Switch
switch (y) {
// If y == 2
case 2:
document.write( "Choice is 2" );
break ;
// If y == 3
case 3:
document.write( "Choice is 3" );
break ;
}
break ;
// If x == 4
case 4:
document.write( "Choice is 4" );
break ;
// If x == 5
case 5:
document.write( "Choice is 5" );
break ;
default :
document.write( "Choice is other than 1, 2 3, 4, or 5" );
} // This code is contributed by Shubham Singh </script> |
Output:
Choice is 2