C Exercises: Change the array elements

Last update on September 19 2025 12:44:46 (UTC/GMT +8 hours)

Reverse the first and last elements of an array

Write a C program that reads an array of integers (length 8), replaces the 1st element with the 8^th, the 2^nd with the 7^th and so on. Print the final array.

Sample Solution:

C Code:

#include <stdio.h>
int main () {
    unsigned short i, j; // Declare variables for looping
    short array_nums[8], n, temp1, temp2; // Declare array and temporary variables

    // Prompt user for input
    printf("Input 8 array elements:\n");

    // Loop to read 8 short values from the user and store them in the array
    for (i = 0; i < 8; i++) {
        scanf("%hd", &n);
        array_nums[i] = n;
    }

    // Loop to swap elements from the first half of the array with the second half
    for (i = 0, j = 7; i <= 4 && j >= 4; i++, j--) {
        temp1 = array_nums[i];
        temp2 = array_nums[j];
        array_nums[i] = temp2;
        array_nums[j] = temp1;
    }

    // Print modified array
    printf("\nModified array:\n");
    for (i = 0; i < 8; i++)
        printf("array_nums[%d] = %d\n", i, array_nums[i]);

    return 0; // End of program
}

Sample Output:

Input 8 array elements:
25
35
17
-5
29
45
60
65

Modified array:
array_nums[0] = 65
array_nums[1] = 60
array_nums[2] = 45
array_nums[3] = 29
array_nums[4] = -5
array_nums[5] = 17
array_nums[6] = 35
array_nums[7] = 25

Flowchart:

C Programming Flowchart: Change the array elements.

For more Practice: Solve these Related Problems:

Write a C program to reverse an array in place by swapping elements from the ends towards the center.
Write a C program to use a two-pointer technique to swap the first and last elements, second and second last, and so on.
Write a C program to reverse the order of an array using recursion and print the modified array.
Write a C program to create a function that reverses an array and demonstrate its use on an 8-element array.

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