Question

How to apply callback to fixed‑size 2D array in C

Answer 1

#include <stdio.h>

// Fixed‑size 2D array

// Callback receives a pointer to each element

void apply(int rows, int cols, int arr[rows][cols], void (*cb)(int*)) {
    for (int r = 0; r < rows; r++) {
        for (int c = 0; c < cols; c++) {
            cb(&arr[r][c]);
        }
    }
}

void increment(int *x) {
    (*x)++;
}

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

    apply(2, 3, arr, increment);

    // Print result
    for (int r = 0; r < 2; r++) {
        for (int c = 0; c < 3; c++)
            printf("%d ", arr[r][c]);
        printf("\n");
    }
}


 
/*
run:
 
2 3 4 
5 6 7 
 
*/

 

70+ SQL courses for beginners and professionals