Question

Here is part of my code. I would like to initialize only the arraylist[0] as arraylist[0].x = 0 and arraylist[0].y = 0. I do not need to initialize the rest of the struct array. How can I do it? Thank you.

#include <stdio.h>
struct example {
    int x;
    int y;
};
struct example arraylist[40];

int main(int argc, char *argv[]){
    printf("%d\n %d\n", arraylist[0].x, arraylist[0].y);
    return 0;
}

Answer 1

You can initialise any particular element of the struct array.

For example:

struct example arraylist[40] = { [0]={0,0}}; //sets 0th element of struct

struct example arraylist[40] = { [5]={0,0}}; //sets 6th element of struct

This is called Designated Initializers which used to be a GNU extension before C99 adapted it and is also supported in standard C since C99.