Nested switch case

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