C Program One Dimensional Array

In this article, you will learn and get code about using one-dimensional (1D) array in a C program. For example,

int arr[10] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10};

The array arr[] is a one dimensional array of size 10. Because in array, indexing starts from 0, therefore all the 10 numbers gets stored in a way that:

• 1 stored at arr[0]
• 2 stored at arr[1]
• 3 stored at arr[2]
• and so on

The last number, 10 gets stored at arr[9]. Let's move on to the program of one-dimensional array given below.

One Dimensional Array Program in C

Here is the program that uses one-dimensional array. The question is, write a program in C, that asks from user to enter size and elements for a one-dimensional array, and print it back as output. The answer to this question is given below:

#include<stdio.h>
#include<conio.h>
int main()
{
    int arr[50], size, i;
    printf("How many Elements You want to store in Array ? ");
    scanf("%d", &size);
    printf("\nEnter %d Elements: ", size);
    for(i=0; i<size; i++)
        scanf("%d", &arr[i]);
    printf("\nElements of this One-dimensional Array is:\n");
    for(i=0; i<size; i++)
        printf("%d ", arr[i]);
    getch();
    return 0;
}

This program was build and run under Code::Blocks Here is the sample run:

Now supply the size for one-dimensional array say 8 and then enter any 8 number one by one say 1, 2, 3, 4, 5, 6, 7, 8 and press ENTER key to see the output as shown in the snapshot given below:

To learn about array in detail, then refer to Arrays in C tutorial. Let's take a look at some of the main steps used in above program.

Steps used in previous Program

These are some of the main steps used in previous program. Supposing that user enters 8 as size and 1, 2, 3, 4, 5, 6, 7, 8 as elements of the array:

• Because user enters 8 as the size for array, then 8 gets initialized to size variable
• Initially the value of i is 0 and 0 is less than the value of size variable
• So program flow goes inside the for loop, scans a value and stores it at the index no. i^th
• Because the value of i is 0, so the first value 1 gets stored at str[0]
• Program flow increments the value of i using the third statement of for loop, and its value becomes 1
• Now 1 again gets checked whether it is less than the value of size or not
• Because 1 is again less than the value of size variable (that holds 8 as its value)
• Then program flow again goes inside the loop, and scans another value
• Stores this value at str[i] or str[1]
• Now again program flow goes to the third statement of for loop that is update part (of loop variable(s)), and increments the value of i
• The value of i becomes 2, and checks whether it is less than the value of size or not
• Because it is less than the value of size variable
• So program flow again goes inside the loop
• Continue the process until the condition of the for loop evaluates to be false, that is when the value of i becomes 8, then it means, 8 is not less than 8 (value of size)
• So program flow exits from the first for loop
• After exiting from the first for loop, we have a one-dimensional array of size 8, where elements are stored in a way that,
  • 1 is at str[0]
  • 2 is at str[1]
  • 3 is at str[2}
  • and so on upto..
  • 8 is at str[7]
• Now use another for loop, to print the entered array, back on the output screen as shown in the program given above. That's it

Same Program in Other Languages

• C++ 1D Array Program
• Java 1D Array Program
• Python 1D Array Program

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