Question

Write a menu driven program to demonstrate the use of array and switch.

It must be written in C language .

Here is the menu -

• Press 1 to add a number to the array.
• Press 2 to display the numbers entered in the array so far
• Press 3 to find the average of the numbers entered.
• Press 4 to exit.

Option 1 - The user should be able to enter 20 numbers only. If all twenty numbers are entered by the user and user selects choice 1, then a message should be displayed saying that the array is full.

Option 2 -The numbers saved in the array that are entered by the user should be displayed. (For example - If user enters one number and then selects menu option 2, then that one number needs to be displayed only. No zeros should be displayed for the rest of the numbers in the array)

Option 3 - Need to display average of all the numbers entered by the user. (hint- use a counter variable to keep track of how many numbers are entered by the user.)

Option 4 - Displays "Thank you" message.
Make sure to turn in the source code with comments and program output screen shots in a word document. No design tool required. Make sure to run various test cases so that I can be convinced that your program is working perfectly for all the menu options.

Answer 1

Here is the code in C below. I've commented it for you for better understanding. Refer to the output below the code and indentation below the output for better formatting of the code.

#include<stdio.h>

void main(){

    //initialising variables

    int arr[20];

    int count=0;

    printf("Press 1 to add a number to the array.\n");

    printf("Press 2 to display the numbers entered in the array so far\n");

    printf("Press 3 to find the average of the numbers entered.\n");

    printf("Press 4 to exit.\n");

    int choice;

    printf("Enter your choice: ");

    scanf("%d",&choice);

    //assuming valid choices are between 1 to 4

    while(choice>=1 && choice<=4){

        switch (choice)

        {

            //entering into array

            case 1:

                if(count<20){

                    //input a number and add it to array

                    printf("Enter a number: ");

                    int num;

                    scanf("%d",&num);  

                    arr[count++]=num;          

                    printf("Number added to array\n");

                }

                else{   //array full

                    printf("Array is full\n");

                }

                break;

            case 2:

            //printing the array using for loop

                printf("Array: ");

                for(int i=0;i<count;i++)

                    printf("%d ",arr[i]);

                printf("\n");

                break;

            case 3:

            //calculating average

                if(count==0){   //empty array

                    printf("Empty Array\n");

                    break;

                }

                printf("Average: ");

                float sum=0;

                for(int i=0;i<count;i++)

                    sum+=arr[i];

                printf("%f \n",sum/count);  //average=sum/count

                break;

            case 4:

            //exit

                printf("Thank you!!");

                return;

        }

        //entering choice in while loop

        printf("Enter your choice: ");

        scanf("%d",&choice);

    }

}

Output

For Indentation Purpose