An array is a collection of elements of the same data type stored in contiguous memory locations. Array indices start at 0.
// Declaration
int numbers[5];
// Declaration with initialization
int numbers[5] = {10, 20, 30, 40, 50};
// Size inferred from initializer
int numbers[] = {10, 20, 30, 40, 50};
// Access element
printf("%d", numbers[0]); // 10
numbers[2] = 99; // modify elementA 2D array is an array of arrays - essentially a matrix with rows and columns.
// Declaration: rows x columns
int matrix[3][4];
// Initialization
int matrix[2][3] = {
{1, 2, 3},
{4, 5, 6}
};
// Access: matrix[row][col]
printf("%d", matrix[1][2]); // 6#include <stdio.h>
int main() {
int scores[] = {85, 92, 78, 95, 88};
int n = sizeof(scores) / sizeof(scores[0]); // number of elements = 5
// Traverse and print
printf("Scores: ");
for (int i = 0; i < n; i++) {
printf("%d ", scores[i]);
}
printf("\n");
// Find sum and average
int sum = 0;
for (int i = 0; i < n; i++) {
sum += scores[i];
}
printf("Sum: %d\n", sum);
printf("Average: %.2f\n", (float)sum / n);
// Find maximum
int max = scores[0];
for (int i = 1; i < n; i++) {
if (scores[i] > max) max = scores[i];
}
printf("Max: %d\n", max);
return 0;
}
/*
Scores: 85 92 78 95 88
Sum: 438
Average: 87.60
Max: 95
*/#include <stdio.h>
int main() {
int a[2][3] = {{1, 2, 3}, {4, 5, 6}};
int b[2][3] = {{7, 8, 9}, {10, 11, 12}};
int c[2][3];
// Matrix addition
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
c[i][j] = a[i][j] + b[i][j];
}
}
// Print result matrix
printf("Matrix A + B:\n");
for (int i = 0; i < 2; i++) {
for (int j = 0; j < 3; j++) {
printf("%4d", c[i][j]);
}
printf("\n");
}
return 0;
}
/*
Matrix A + B:
8 10 12
14 16 18
*/#include <stdio.h>
// Arrays are always passed by reference (pointer to first element)
int findMax(int arr[], int size) {
int max = arr[0];
for (int i = 1; i < size; i++) {
if (arr[i] > max) max = arr[i];
}
return max;
}
void printArray(int arr[], int size) {
for (int i = 0; i < size; i++) {
printf("%d ", arr[i]);
}
printf("\n");
}
// Passing 2D array to function
void print2D(int rows, int cols, int arr[rows][cols]) {
for (int i = 0; i < rows; i++) {
for (int j = 0; j < cols; j++) {
printf("%4d", arr[i][j]);
}
printf("\n");
}
}
int main() {
int nums[] = {34, 12, 67, 45, 89, 23};
int n = sizeof(nums) / sizeof(nums[0]);
printf("Array: ");
printArray(nums, n);
printf("Max element: %d\n", findMax(nums, n));
int matrix[2][3] = {{1, 2, 3}, {4, 5, 6}};
printf("\n2D Array:\n");
print2D(2, 3, matrix);
return 0;
}
/*
Array: 34 12 67 45 89 23
Max element: 89
2D Array:
1 2 3
4 5 6
*/Explore 500+ free tutorials across 20+ languages and frameworks.