C : What is the purpose of the 'union programmingLang' in this C program ?

Program :

#include<stdio.h>

union programmingLang
{
    char pName[50];
    int rank;
};

int main()
{
    union programmingLang prm[5];

    printf("Enter your 5 favourite programming languages  :\n");

    for(int i=0; i<5; i++) {
        scanf("%s", &prm[i].pName);
    }

    printf("\nList of favourite programming languages : \n");

    for(int i=0; i<5; i++) {
        printf("%s\n", prm[i].pName);
    }

    return 0;
}

Output :

Explanation :

This C program allows a user to input their 5 favorite programming languages and then displays the list of these languages. Here’s a step-by-step explanation:

1. The program includes the standard input/output library (`#include <stdio.h>`).

2. It defines a union named "programmingLang," which can store either an array of 50 characters (for the name of a programming language) or an integer (for the rank of a programming language).

3. In the `main()` function:
- It declares an array `prm` of five `programmingLang` unions. This array will hold the input data.
- It prompts the user to enter their 5 favorite programming languages using `printf`.

4. It then uses a `for` loop to iterate five times, and within each iteration:
- It uses `scanf` to read a string (the name of a programming language) from the user and store it in the `pName` field of the `programmingLang` union. The `&` operator is used because `scanf` expects a pointer to the variable where it should store the input.
- The user's input is stored in `prm[i].pName`.

5. After collecting the input, the program displays the list of favorite programming languages using another `for` loop:
- It prints each of the stored language names (in `prm[i].pName`) using `printf`.

6. Finally, the program returns 0, indicating successful execution.

Note: This program uses a `union` to store either a string (array of characters) or an integer for each entry in the array, but it doesn't use the `rank` field in this code. Also, it doesn't provide any error handling for input exceeding the 50-character limit, which may lead to buffer overflow issues.

(explanation and title credit goes to CHAT GPT)