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Segmentation fault when accessing elements of a dynamically allocated 2D array in C

👀 Views: 256 đŸ’Ŧ Answers: 1 📅 Created: 2025-06-05
c memory-management segmentation-fault C

I tried several approaches but none seem to work. I've searched everywhere and can't find a clear answer. I'm working with a segmentation fault when trying to access elements of a dynamically allocated 2D array. I'm using C11 and have allocated the array using a pointer-to-pointer approach. Here's the relevant code snippet: ```c #include <stdio.h> #include <stdlib.h> int main() { int rows = 3; int cols = 4; int **array; // Allocating memory for the rows array = malloc(rows * sizeof(int *)); for (int i = 0; i < rows; i++) { // Allocating memory for the columns array[i] = malloc(cols * sizeof(int)); } // Initializing the array for (int i = 0; i < rows; i++) { for (int j = 0; j < cols; j++) { array[i][j] = i * cols + j; } } // Trying to access an out-of-bounds element printf("Element at array[3][2]: %d\n", array[3][2]); // This line causes a segmentation fault // Freeing the allocated memory for (int i = 0; i < rows; i++) { free(array[i]); } free(array); return 0; } ``` I expected the program to print the value of the element at index [3][2], but instead, it crashes with a segmentation fault. I've confirmed that the memory allocation is successful, as I checked the pointers immediately after the `malloc` calls. It seems like I'm accessing an index that doesn't exist, but I thought that array indices were zero-based. How can I fix this scenario? Am I using the right approach for allocation? Any insights would be appreciated! My development environment is Ubuntu. What's the best practice here? This is part of a larger web app I'm building. Am I missing something obvious?