Arrays, Vectors, and Strings in C: A Complete Guide with Examples

Arrays, Vectors and Strings in C
In C, arrays, vectors, and strings are used to store multiple values. Understanding
how to use them is crucial for managing large amounts of data and handling
dynamic memory.

1. Arrays in C
An array is a collection of variables of the same type that are stored in contiguous
memory locations. It allows you to store multiple values in a single variable.

1.1. Declaring and Initializing Arrays

To declare an array in C, specify the data type, the array name, and the size of the
array. For example:

#include <stdio.h>

int main() {
int numbers[5]; // Declaring an array of 5 integers

// Initializing an array
numbers[0] = 10;
numbers[1] = 20;
numbers[2] = 30;
numbers[3] = 40;
numbers[4] = 50;

// Accessing array elements
for (int i = 0; i < 5; i++) {
printf("Element %d: %d\n", i, numbers[i]);
}

return 0;
}

, 1.2. Array Initialization

You can initialize an array at the time of declaration:

#include <stdio.h>

int main() {
int numbers[] = {10, 20, 30, 40, 50}; // Size is automatically determined

// Accessing array elements
for (int i = 0; i < 5; i++) {
printf("Element %d: %d\n", i, numbers[i]);
}

return 0;
}

1.3. Multi-Dimensional Arrays

C supports multidimensional arrays, where each element is itself an array. A
common use case is a matrix.

#include <stdio.h>

int main() {
int matrix[2][3] = {{1, 2, 3}, {4, 5, 6}}; // 2x3 matrix

// Accessing elements of a 2D array
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
printf("Element at [%d][%d]: %d\n", i, j, matrix[i][j]);
}
}

return 0;
}