Try It Yourself - SyntaxStudy Editor

HTML / CSS / JS

#include <stdio.h>

#define ROWS 3
#define COLS 4

void print_matrix(const int mat[][COLS], int rows)
{
    for (int r = 0; r < rows; r++) {
        for (int c = 0; c < COLS; c++)
            printf("%4d", mat[r][c]);
        printf("
");
    }
}

int main(void)
{
    /* 1D array initialisation */
    int arr[] = {10, 20, 30, 40, 50};
    int n = sizeof(arr) / sizeof(arr[0]);

/* Index-based access */
    printf("arr[2] = %d
", arr[2]);    /* 30 */

/* Pointer arithmetic — equivalent ways to traverse */
    int *p = arr;
    for (int i = 0; i < n; i++)
        printf("%d ", *(p + i));        /* same as arr[i] */
    printf("
");

/* Pointer walking */
    for (int *q = arr; q < arr + n; q++)
        printf("%d ", *q);
    printf("
");

/* 2D array */
    int mat[ROWS][COLS] = {
        { 1,  2,  3,  4},
        { 5,  6,  7,  8},
        { 9, 10, 11, 12}
    };
    print_matrix(mat, ROWS);

/* Flatten 2D to 1D pointer arithmetic */
    int *flat = &mat[0][0];
    printf("Element [1][2] via flat pointer: %d
",
           flat[1 * COLS + 2]);          /* 7 */

return 0;
}