Arrays

 Chapter 8: Arrays

 

Arrays in C allow you to store multiple values of
the same data type in a contiguous memory block. They provide an efficient way
to work with collections of data. Let's explore how to declare, initialize, and
access elements in arrays:

 

8.1
Array Declaration:

To declare an array in C, you need to specify the
data type of the elements and the size of the array.

 

data_type
array_name[size];

 

Example:

#include
<stdio.h>

int
main() {

    int numbers[5]; // Declaration of an integer
array

 

    return 0;

}

 

The program declares an integer array `numbers` with
a size of 5 elements. Remember that arrays are zero-indexed, so the indexes
range from 0 to size-1.

 

8.2
Array Initialization:

Arrays can be initialized at the time of declaration
using an initializer list.

 

 

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

 

Example:

#include
<stdio.h>

 

int
main() {

    int numbers[5] = {2, 4, 6, 8, 10}; //
Initialization of an integer array

 

    return 0;

}

 

 

The program declares and initializes an integer
array `numbers` with the values 2, 4, 6, 8, and 10.

 

8.3
Accessing Array Elements:

You can access individual elements in an array using
the array name followed by the index in square brackets.

array_name[index]

 

Example:

#include
<stdio.h>

int
main() {

    int numbers[5] = {2, 4, 6, 8, 10};

 

    printf("First element: %d\n",
numbers[0]);

    printf("Third element: %d\n",
numbers[2]);

 

    return 0;

}

 

The program accesses and prints the first and third
elements of the `numbers` array. Compile and run the program to see the output.

 

8.4
Modifying Array Elements:

You can modify the value of an array element by
assigning a new value to it.

 

array_name[index]
= new_value;

 

 

Example:

 

#include
<stdio.h>

int
main() {

    int numbers[5] = {2, 4, 6, 8, 10};

 

    numbers[1] = 3; // Modifying the second
element

    printf("Modified second element:
%d\n", numbers[1]);

 

    return 0;

}

 

 

The program modifies the value of the second element
in the `numbers` array and prints the modified value. Compile and run the
program to see the output.

 

8.5
Looping through Arrays:

You can use loops to iterate over the elements of an
array and perform operations on them.

Example:

#include
<stdio.h>

int
main() {

    int numbers[5] = {2, 4, 6, 8, 10};

 

    int i;

    for (i = 0; i < 5; i++) {

        printf("%d ", numbers[i]);

    }

 

    printf("\n");

 

    return 0;

}

 

 

The program uses a for loop to iterate over the
elements of the `numbers` array and prints them. Compile and run the program to
see the output.

 

8.6
Multidimensional Arrays:

C supports multidimensional arrays, which are arrays
of arrays. They can be used to represent matrices, tables, and other structured
data.

 

Example:

#include
<stdio.h>

int
main() {

    int matrix[3][3] = {

        {1,

 

 2, 3},

        {4, 5, 6},

        {7, 8, 9}

    };

 

    printf("Element at (1, 2): %d\n",
matrix[1][2]);

 

    return 0;

}

 

The program declares and initializes a 2-dimensional
integer array `matrix`. It accesses and prints the element at index (1, 2).
Compile and run the program to see the output.