How to Modify Array Elements in C – A Beginner's Guide

Here’s a beginner-friendly blog post explaining the provided C program that uses arrays. How to Modify Array Elements in C – A Beginner’s Guide

Introduction
In this tutorial, we’ll look at a simple program that initializes an array, prints its elements, modifies them, and then prints the modified array. This is a great way to understand how arrays work in C and how we can change array elements.

Understanding the Program

In C, an array is a way to store multiple values of the same data type. Here, we’ll declare an array called marks and then explore how to initialize, access, and modify each element of the array.

Let’s dive into the code step-by-step.

Code

#include<stdio.h>

void main() {
    int marks[3] = {10, 20, 30}; // Initializing the array with values

    // Printing original array elements
    for(int i = 0; i < 3; i++) {
        printf("%d ", marks[i]);
    }
    printf("\n");

    // Modifying array elements
    marks[0] = 1;
    marks[1] = 1;
    marks[2] = 1;

    // Printing modified array elements
    for(int i = 0; i < 3; i++) {
        printf("%d ", marks[i]);
    }
}

Explanation

Declaring and Initializing the Array

   int marks[3] = {10, 20, 30};

Here, we declare an integer array called marks with a size of 3. This array is initialized with three values: 10, 20, and 30.

Printing the Original Array Elements

   for(int i = 0; i < 3; i++) {
       printf("%d ", marks[i]);
   }

This loop goes through each element in the marks array and prints its value.
When i is 0, it prints marks[0], which is 10.
When i is 1, it prints marks[1], which is 20.
When i is 2, it prints marks[2], which is 30.

Modifying the Array Elements

   marks[0] = 1;
   marks[1] = 1;
   marks[2] = 1;

Here, we change the values of each element in the array.
marks[0], marks[1], and marks[2] are all set to 1.

Printing the Modified Array Elements

   for(int i = 0; i < 3; i++) {
       printf("%d ", marks[i]);
   }

After modifying the elements, we again use a loop to print the new values.
This time, since each element is set to 1, the output will show 1 1 1.

Complete Output

When you run this code, you’ll see:

10 20 30 
1 1 1

The first line displays the initial values of the array (10 20 30).
The second line displays the modified values of the array after setting each element to 1 (1 1 1).

Conclusion

In this program, we learned how to:

Declare and initialize an array.
Access and print each element in an array.
Modify the elements in an array.

Arrays in C allow us to store and manipulate multiple values easily. By practicing modifying array elements as shown here, you can develop a strong foundation for using arrays in larger programs.

Happy Coding!