How to initialize all members of an array to the same value?

Question

I have a large array in C (not C++ if that makes a difference). I want to initialize all members to the same value. I could swear I once knew a simple way to do this. I could use `memset()` in my case, but isn't there a way to do this that is built right into the C syntax?

Answer 1

Yes, there's a syntax for initializing C/C++ array [simple type] elements with like values in a declaration, and a way to re-assign like values at any point in runtime ... See simple test program below, and its output:

#include <stdio.h>

#include <string.h>

#define SIZE 512

int main() {

char array[SIZE] = { [ 0 ... SIZE-1 ] = 65 }; // assign 'A' to all 512 elements

// display some random elements

printf("%c\n", array[0]);

printf("%c\n", array[50]);

printf("%c\n", array[500]);

memset(array, 66, SIZE); // assign 'B' to all 512 elements

// display some random elements

printf("%c\n", array[0]);

printf("%c\n", array[50]);

printf("%c\n", array[500]);

}

OUTPUT

A

A

A

B

B

B