Question

1. Build and present a menu to a user like the following and enclose it into a loop that ends when the Quit option is chosen. Scan the user's selection into an integer variable.

   1.  Enter user name.
   2.  Enter test scores.
   3.  Display average.
   4.  Display summary.
   5.  Quit.
   Selection:

2. If the user selects Option #1, scan the user's name, and store it to a char array. Assume the user's name is under 20 characters.
   
3. If the user selects Option #2, use a for-loop to scan 3 exam scores into a float array. Calculate the average and store the result in a float variable. Assume all scores are out of 100 points.  
   
4. If the user selects Option #3, Display the average of the test scores. If the user has not yet entered test scores, display an error message similar to: "Please use the menu to enter test scores first"
   
   Hint: Use boolean values to keep track of the options that have been selected.
   
5. If the user selects Option #4, display the average, the letter grade of the average, and the user's name. If the user has not yet entered their name or test scores, display an error message.
   
   Example: "Hello Charley, your test scores were 80, 90, and 100. Your average is 90.0 with letter grade: A."
   Example: "Please use the menu to enter your name first."
   Example: "Please use the menu to enter your test scores first."
   
6. When the Quit option is chosen, end the primary loop that contains the menu.

c++ please

for while do while

could you write a c program please?

Answer 1

NOTE: If you have any query regarding the solution, please ask in comment section! HAPPY LEARNING!!

There will not be too much difference in the code for language c and c++, but still I have provided the code in both language for better understanding, and the code is done in the same way as in problem statement explained.

CODE (C++):

#include<iostream>
using namespace std;


void display_average(float scores[]){                   // FUNCTION FOR DISPLAY AVERAGE
    float sum = 0.0;
    for(int i=0;i<3;i++)
        sum += scores[i];                               // ADDED ALL THE SCORES AND DIVIDED BY NUMBER OF SCORES TO CALCULATE AVERAGE

    float average = sum/3;
    cout<<"Your average score is "<<average<<endl;      // PRINTED THE AVERAGE

}
void display_summary(char name[],float scores[]){       // FUNCTION FOR DISPLAY SUMMARY

    float sum = 0.0;
    for(int i=0;i<3;i++)
        sum += scores[i];

    float average = sum/3;                              // CALCULATED THE AVERAGE IN THE SAME WAY AS ABOVE
    char grade;
    if (average>=90)                                    // CALCULATED THE GRADE ACCORDING TO THE AVERAGE CALCULATED
        grade = 'A';
    else if (average>=80)
        grade = 'B';
    else if (average>=70)
        grade = 'C';
    else if (average>=60)
        grade = 'D';
    else
        grade = 'F';
                                                        // PRINTED THE SUMMARY AS SPECIFIED IN THE PROBELEM DESCRIPTION

    cout<<"Hello "<<name<<", your test scores were "<<scores[0]<<", "<<scores[1]<<" and "<<scores[2]<<". Your average is "<<average<<" with letter grade: "<<grade<<"."<<endl;


}

int main(){                                             // MAIN FUNCTION
    char name[20];
    float test_scores[3];                               // TEST SCORES ARRAY OF SIZE 3 TO STORE THE SCORES OF 3 SUBJECTS
    bool name_entered =false, scores_entered = false;   // BOOLEAN VARIABLES FOR THE PROGRAM TO KNOW IF USER HAS ENTERED THE NAME AND SCORES OR NOT
    int choice;

    while (1){
        cout<<"\n1. "<<"Enter User Name."<<endl;        // DISPLAY THE MENU
        cout<<"2. "<<"Enter Test Scores."<<endl;
        cout<<"3. "<<"Display Average."<<endl;
        cout<<"4. "<<"Display Summary."<<endl;
        cout<<"5. "<<"Quit."<<endl;
        cout<<"\nEnter your choice: ";
        cin>>choice;

        switch(choice){                                 // GO TO THE CASE BY SWITCH AS THE CHOICE ENTERED
            case 1:
                cin>>name;                              // TAKE THE NAME INPUT FROM USER AND ASSIGN TRUE TO THE BOOLEAN VARIABLE NAME_ENTERED
                name_entered = true;
                break;
            case 2:
                for(int i=0;i<3;i++)
                    cin>>test_scores[i];                // TAKE THE SCORES OF THE THREE SUBJECTS AND ASSIGN TRUE TO THE BOOLEAN VARIABLE SCORES ENTERED
                scores_entered = true;
                break;
            case 3:
                if (!scores_entered)                    // IF SCORES NOT ENTERED DISPLAY ERROR ELSE CALL THE DISPLAY AVERAGE FUNCTION
                    cout<<"Please use the menu to enter test scores first"<<endl;
                else
                    display_average(test_scores);
                break;
            case 4:
                if(!name_entered)
                    cout<<"Please use the menu to enter your name first"<<endl;     // IF NAME OR SCORES OR BOTH NOT ENTERED DISPLAY THE ERROR ELSE CALL THE DISPLAY SUMMARY FUNCTION
                if(!scores_entered)
                    cout<<"Please use the menu to enter test scores first"<<endl;
                if(name_entered && scores_entered)
                    display_summary(name,test_scores);
                break;
            case 5:
                exit(0);
            default:
                cout<<"Invalid choice!!! please try again..."<<endl;           // IF CHOICE IS INVALID DISPLAY ERROR


        }
    }
    return 0;
}

CODE (C):

#include<stdio.h>
#include<stdlib.h>
void display_average(float scores[]){
    float sum = 0.0,average;
    int i;
    for(i=0;i<3;i++)
        sum += scores[i];

    average = sum/3;
    printf("Your average score is %.2f\n",average);

}
void display_summary(char name[],float scores[]){

    float sum = 0.0,average;
    int i;
    char grade;
    for(i=0;i<3;i++)
        sum += scores[i];

    average = sum/3;
    if (average>=90)
        grade = 'A';
    else if (average>=80)
        grade = 'B';
    else if (average>=70)
        grade = 'C';
    else if (average>=60)
        grade = 'D';
    else
        grade = 'F';

    printf("Hello %s, your test scores were %.1f, %.1f and %.1f. Your average is %.2f with letter grade: %c\n",name,scores[0],scores[1],scores[2],average,grade);


}

int main(){
    char name[20];
    float test_scores[3];
    int name_entered = 0, scores_entered = 0;           // IN C LANGUAGE BOOLEAN IS NOT DEFINED SO TOOK INTEGER VALUE 0 FOR FALSE AND 1 FOR TRUE
    int choice,i;

    while (1){
        printf("\n1. Enter User Name.");
        printf("\n2. Enter Test Scores.");
        printf("\n3. Display Average.");
        printf("\n4. Display Summary.");
        printf("\n5. Quit.\n");
        printf("\nEnter your choice: ");
        scanf("%d",&choice);

        switch(choice){
            case 1:
                scanf("%s",name);
                name_entered = 1;
                break;
            case 2:
                for(i=0;i<3;i++)
                    scanf("%f",&test_scores[i]);
                scores_entered = 1;
                break;
            case 3:
                if (!scores_entered)
                    printf("\nPlease use the menu to enter test scores first\n");
                else
                    display_average(test_scores);
                break;
            case 4:
                if(!name_entered)
                    printf("\nPlease use the menu to enter your name first");
                if(!scores_entered)
                    printf("\nPlease use the menu to enter test scores first\n");
                if(name_entered && scores_entered)
                    display_summary(name,test_scores);
                break;
            case 5:
                exit(0);
            default:
                printf("\nInvalid choice!!! please try again...\n");


        }
    }
    return 0;
}

OUTPUT SCREENSHOT( INPUT INCLUDED) :