Initialization of variables sized arrays in C
The C99 standard allows variable sized arrays (see this). But, unlike the normal arrays, variable sized arrays cannot be initialized.
For example, the following program compiles and runs fine on a C99 compatible compiler.
#include<stdio.h> int main(){ int M = 2; int arr[M][M]; int i, j; for (i = 0; i < M; i++) { for (j = 0; j < M; j++) { arr[i][j] = 0; printf ("%d ", arr[i][j]); } printf("\n"); } return 0;} |
Output:
0 0 0 0
But the following fails with compilation error.
#include<stdio.h> int main(){ int M = 2; int arr[M][M] = {0}; // Trying to initialize all values as 0 int i, j; for (i = 0; i < M; i++) { for (j = 0; j < M; j++) printf ("%d ", arr[i][j]); printf("\n"); } return 0;} |
Output:
Compiler Error: variable-sized object may not be initialized
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