Passing an array as function argument without defining a variable [duplicate]

Question

How can we pass an array directly to a function in C?

For example:

#include <stdio.h>

void function(int arr[]) {};

int main(void) {
    int nums[] = {3, -11, 0, 122};
    function(nums);
    return 0;
}

Instead of this, can we just write something like function({3, -11, 0, 122});?

One option is to wrap the array inside a struct: struct foo { int arr[10]; }; struct foo wrapped = {{3, -11, 0, 122}}; fx(wrapped); — pmg
– pmg, Commented Jan 11, 2021 at 8:06
Ah! Didn't read the question title with enough attention; anyway leaving the comment here :-) — pmg
– pmg, Commented Jan 11, 2021 at 8:08
@pmg Not your fault sir, I expanded the title based on my understanding of the question. the initial version had no mention of that. Apologies. — Sourav Ghosh
– Sourav Ghosh, Commented Jan 11, 2021 at 8:10
"can we just write something like" - What happened when you tried? — klutt
– klutt, Commented Jan 11, 2021 at 8:11

Sourav Ghosh · Accepted Answer · 2021-01-11 08:03:18Z

7

You can make use of a compound literal. Something like

function((int []){3, -11, 0, 122});

answered Jan 11, 2021 at 8:03

Sourav Ghosh

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2 Comments

One of those things that work in C but not C++, I think.

@dxiv: it works in C99 and later, but not in C++ (yet?).

kiran Biradar · Accepted Answer · 2021-01-11 08:03:06Z

5

You could pass array as compound literal as below.

function((int []){3, -11, 0, 122});

answered Jan 11, 2021 at 8:03

kiran Biradar

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