One Dimensional Array in C – Definition, Types, Example & Algorithm

Updated on July 22, 2024

Article Outline

What is an Array in C?Types of Arrays Introduction to One-Dimensional Array in C Rules for Declaring One-Dimensional Array in C Array Initialization Access Array Elements Update Array Element Array Traversal in Array Copying One-Dimensional in C Common Operations and Functions on One-Dimensional Arrays Points to Remember About Array in C Importance of One-Dimensional Arrays in Computer Programming Conclusion FAQs

One-dimensional arrays are a fundamental data structure in computer programming, particularly in the C language. They allow you to store the same type of data in the memory, providing a simple and efficient way to store multiple values in a single variable. In this article, we will delve into the world of one-dimensional arrays in C.

What is an Array in C?

An array is a collection of one or more elements in the same data type. It is stored in contiguous memory locations and can be any type, such as int, char, float, etc. We can also use arrays with user-defined data types, such as pointers, structures, etc.

Example of Arrays

// This program illustrates the Arrays in c language

#include <stdio.h>

int main()

{

// declaring an array of integers

int arr_int[5];

// declaring array of characters

char arr_char[5];

 

return 0;

}

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Types of Arrays

There are three types of Arrays in C language:

One-dimensional Arrays
Two-dimensional Arrays
Multi-dimensional arrays

Introduction to One-Dimensional Array in C

We can imagine one-dimensional arrays in C as a single row storing the elements. In an Array, All the elements are stored in a contiguous memory location in Arrays. Array elements can be accessed using the indexing.

1 dimension array

● Arrays Declarations

In the C language, Array declarations are very easy. Arrays can be any type, such as int or char. We can give any to the arrays, just like a random variable in C language.

Syntax of Array Declaration

int arr[5]; // Size of array is 5 in this declarations

Rules for Declaring One-Dimensional Array in C

The following rules must be followed before declaring the One Dimensional Array in C language.

Before accessing and using an array, we must declare the array variable.
The array can be accessed using indexing. The first element index is 0 in Array.
Each element in the array is stored in contiguous memory locations.
If you are defining the size of the array. It must be a non-negative number.
Write a valid array name using the identifier. Which must be easily readable in the source code.

Array Initialization

Initizalations is the process where we define the elements of the array. When we declare an array or allocate the memory element of the array. Starting arrays contain some garbage value. So, we need to initialise the array to some meaningful value. In C language, we can initialise an array in different ways. Let’s explore each way one by one.

● Arrays Initialization with Declaration:

In this method, we will initialise the array along with its declarations. An array can be initialised using the curly braces {}. All those elements will be inserted in these curly brackets and separated by the comma

Syntax:

data_type array_name [size] = {value1, value2, … valueN};

The following program demonstrates the array initialization with declarations

Program

// This program illustrates the Arrays in c language

#include <stdio.h>

int main()

{

// declaring an array of integers

int arr_int[5] = {33,45,55,99,100};

int length = sizeof(arr_int) / sizeof(arr_int[0]);

for(int i = 0;i<length;i++){

printf("%d ",arr_int[i]);

}

 

return 0;

}

Output

33 45 55 99 100

● Arrays Initialization with Declarations without Size

In this section, we will initialise the array without defining its size. In these cases, a compiler can automatically deduce the size of the array, and the compiler will allocate the computer’s memory according to the size of the elements.

Syntax of declaration

data_type array_name[] = {1,2,3,4,5};

The following program demonstrates the array initialization with declarations without size.

Program

// This program illustrates the Arrays in c language

#include <stdio.h>

int main(){

// declaring an array of integers

int arr_int[] = {33,45,55,99,100};

int length = sizeof(arr_int) / sizeof(arr_int[0]);

for(int i = 0;i<length;i++){

printf("%d ",arr_int[i]);

}

 

return 0;

}

Output

33 45 55 99 100

● Arrays Initialization after Declarations (Using loops)

In this section, we will initialise the array using a loop, while loop, or do-while loop to assign a value to each element.

Syntax of loop

for (int i = 0; i < N; i++) {

array_name[i] = valuei;

}

The following program demonstrates the Example of Array initialization in C language.

Program

// C Program to demonstrate array initialization

#include <stdio.h> 

int main(){

// array initialization using an initializer list

int arr[5] = { 10, 20, 30, 40, 50 };

int arr1[] = { 1, 2, 3, 4, 5 };
 

// array initialization using for loop

int arr2[5];

for (int i = 0; i < 5; i++) {

arr2[i] = arr[i] * arr[i] ;

}

for(int j = 0;j<5;j++){

printf("%d ",arr2[j]);

}    return 0;

}

Output

100 400 900 1600 2500

Access Array Elements

We can access array elements using indexing in the C language. We pass the index value in the subscript operator [] and the index value i of the element.

Syntax

array_name [index];

Always remember that an array’s first elements start with index 0, and the last element is at N-1, where N is the number of elements in the array, and N-1 is the last number.

The following program demonstrates the Array Elements using Array Subscript.

Program

// C Program to illustrate element access using an array

// subscript

#include <stdio.h>

int main()

{

// array declaration and initialization

int arr[5] = { 153, 2534, 35, 425, 255 };

// accessing element at index 2, i.e 3rd element

printf("Element at arr[2]: %dn", arr[2]);

// accessing element at index 4, i.e last element

printf("Element at arr[4]: %dn", arr[4]);

// accessing element at index 0, i.e first element

printf("Element at arr[0]: %d", arr[0]);

return 0;

}

Output

Element at arr[2]: 35

Element at arr[4]: 255

Element at arr[0]: 153

Update Array Element

We can also update the value of an element in the array using the subscript operator [] and assignment operator =.

Syntax:

array_name[i] = new_value;

The following program demonstrates the update of the array using the array element.

Program

// C Program to illustrate element access using an array

// subscript

#include <stdio.h>

 

int main()

{

// array declaration and initialization

int arr[5] = { 153, 2534, 35, 425, 255 };

// accessing element at index 2, i.e 3rd element

printf("Old Value = %dn",arr[2]) ;

arr[2] = 33 ;

printf("Update Value = %d",arr[2]) ;

 

return 0;

}

Output

Old Value = 35

Update Value = 33

Array Traversal in Array

In C language, we traverse the array, which is the process of visiting every element of the array. We can traverse the array using loops, while loops do while loops, and for loops.

Traversing using for loop

for (int i = 0; i < N; i++) {

array_name[i];

}

The following program demonstrates the Array Traversal in Array

Program

// C Program to illustrate element access using an array

// subscript

#include <stdio.h>

int main()

{

// array declaration and initialization

int arr[5] = { 153, 2534, 35, 425, 255 };

// accessing element at index 2, i.e 3rd element

int length = sizeof(arr) / sizeof(arr[0]) ;
 
for(int i = 0 ;i< length;i++){

printf("%d ",arr[i]) ;

}

return 0;

}

Output

153 2534 35 425 255

Copying One-Dimensional in C

In this section, we will copy one array to another array. Suppose we have two arrays, array1 and array2. One is initialised with some elements. We have to copy the first array to another array. Let’s see “how we can do this “

The following program demonstrates the Copy one array to another.

Program

#include <stdio.h> 

int main() {

int array1[5] = {100, 240, 330, 440, 550};

int array2[5];
 

printf("Copying One-Dimensional Arrays in C:n");

printf("Array1 elements: ");
 

for (int i = 0; i < 5; i++) {

printf("%d ", array1[i]);

array2[i] = array1[i]; // Copying array1 elements to array2

} 

printf("nArray2 elements after copying: "); 

for (int i = 0; i < 5; i++) {

printf("%d ", array2[i]);

}

}

Output


Copying One-Dimensional Arrays in C:

Array1 elements: 100 240 330 440 550

Array2 elements after copying: 100 240 330 440 550

Common Operations and Functions on One-Dimensional Arrays

In this section, we will discuss the common operations of one-dimensional arrays. We will perform some operations like searching, sorting, modifying elements, and mathematical calculations.

● Searching

Finding specific elements in one-dimensional arrays is a very basic operation in C. We will find specific elements using the linear search. The following program demonstrates the Source Code.

Program

#include <stdio.h> 

// Function to perform linear search

int linearSearch(int arr[], int size, int key) {

for (int i = 0; i < size; i++) {

if (arr[i] == key) {

return i;

}

}

return -1;

} 

int main() {

int numbers[] = {5, 3, 9, 1, 7, 2, 8};

int key = 7;

int size = sizeof(numbers) / sizeof(numbers[0]); 

int index = linearSearch(numbers, size, key); 

if (index != -1) {

printf("Element %d found at index %d.n", key, index);

} else {

printf("Element %d not found in the array.n", key);

} 

return 0;

}

<strong>Output</strong><strong> </strong>

Element 7 found at index 4.

● Sorting

In this section, we will learn to sort with one-dimensional arrays. Sorting is the process of sorting the elements in ascending and descending order. Ascending order means smallest to highest element, and descending order means highest to the smallest element.

The following program demonstrates the Sorting in C language using Bubble Sort.

Program

#include <stdio.h> 

// Function to perform bubble sort

void bubbleSort(int arr[], int size) {

for (int i = 0; i < size - 1; i++) {

for (int j = 0; j < size - i - 1; j++) {

if (arr[j] > arr[j + 1]) {

// Swap arr[j] and arr[j+1]

int temp = arr[j];

arr[j] = arr[j + 1];

arr[j + 1] = temp;

}

}

}

} 

int main() {

int numbers[] = {5, 3, 9, 1, 7, 2, 8};

int size = sizeof(numbers) / sizeof(numbers[0]); 

printf("Array before sorting:n");

for (int i = 0; i < size; i++) {

printf("%d ", numbers[i]);

}

printf("n"); 

bubbleSort(numbers, size); 

printf("Array after sorting:n");

for (int i = 0; i < size; i++) {

printf("%d ", numbers[i]);

}

printf("n"); 

return 0;

}

<strong>Output</strong> 

Array before sorting:

5 3 9 1 7 2 8

Array after sorting:

1 2 3 5 7 8 9

Points to Remember About Array in C

Every developer must know some points about Array. In this section, we will cover those points. Let’s discuss those points.

Arrays in C are collections of similar data type elements stored at contiguous memory locations.
In C array elements can be accessed by the index value.
Array Indexing starts from 0, and the last value of the index is N-1. N is the number of elements present in the array.
Array size can be defined in brackets of the array, for example, int arr[2].

Importance of One-Dimensional Arrays in Computer Programming

In this section, we will talk about the importance of One Dimensional Arrays in Computer programming

ng.

Structure Data Storage: One-dimensional arrays provide a way to store data and store a sequence of elements in a linear format and ensure that data is organised and easily accessible for any developer.
Efficient Memory Usage: Arrays are stored in a contiguous memory location, which makes them efficient in memory and provides fast performance and access to the elements.
Iterating Easy: In Array, Iterating is very easy as compared to other data structures like linked lists.
Simplicity in Implementation: Arrays are excellent data structures to learn about memory and organisation of data structures.

Conclusion

In this article, we learned about one-dimensional arrays in the C language. This is fundamental for anyone venturing into programming. Arrays provide a powerful tool for string manipulation and manipulating data in structured manners, with various types and sizes available. We also learned about the various operations on the array.

FAQs

What is one Dimension Array in C language?

A One-Dimensional Array is the simplest array form in C language. It stores elements in contiguous memory locations. It can be accessed by indexing. For example: ‘int arr[3] = {33,44,55}.

What is the syntax of an array?

In C language, Arrays can be defined with square brackets. In square brackets, define the size of the array. For example, int arr[n].

How to calculate array size in C langauge?

In C, there is no method for finding the length of an array. However, we can find the length of the array using the sizeof() method. Divide the total amount of memory by the size of one element in C.

How do you traverse a one-dimensional array in C language?

We can traverse a one-dimensional array using loops such as ‘for’ or ‘while' loops by iterating over the array indices. We can also access the array elements using the loop with indexing.

What are the advantages of using one-dimensional arrays in C language?

One-dimensional arrays provide a simple and efficient way to store elements in the C language. They can easily manipulate collections of data elements of the same type. They are commonly used for various tasks, such as sequence and ordered collections of items.

Updated on July 22, 2024

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