Program to Read and Reverse an Array in C | C Program

Here's a C program to read and reverse an array. This can easily be done with the help of for loop. This program uses C concepts like For Loop in C, Auto Incrementing Operator ++ and Auto Decrementing Operator --.

# include <stdio.h>
# include <conio.h>
void main() 
{ 
 int a[20], i, n ; 
 clrscr() ; 
 printf("Enter the limit : ") ; 
 scanf("%d", &n) ; 
 printf("\nEnter the elements :\n\n") ; 
 for(i = 0 ; i < n ; i++) 
  scanf("%d", &a[i]) ; 
 printf("\nThe reversed array is :\n\n") ; 
 for(i = n - 1 ; i >= 0 ; i--) 
  printf("%d\t", a[i]) ; 
 getch() ; 
} 

Output of above program is 

Enter the limit : 5

Enter the elements :

20      30      50      10      40

The reversed array is :

40      10      50      30      20

Explanation of above program

Here we have an array a[20] of type integer and size 20. First we ask the user to enter a limit or number of elements he wants to be in that array. After that using a for loop we populates the array up to that limit that user entered.

Now to print the values of an array in reverse order i.e. (n - 1)^th value first, we simply have to use a for loop that starts at the value of i = n - 1, decrementing that value by 1 after each iteration until the value of i becomes less than 0. So the loop will run in reverse direction and hence printing the array values in reverse order. 

Values of loop variable will be like this - (n -1), (n -2), (n -3),........, 3, 2, 1, 0.