countof(3)

✨ countof(3) — the Library Functions Manual glow-up ✨

okay bestie, gather round, we're in section 3 of the manual and this one is so useful it's basically main character energy 🫶

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🌸 NAME 🌸

countof, _Countof — literally just counts how many elements are in an array 💅

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📚 LIBRARY 📚

Standard C library (libc) — she's iconic, she's everywhere, no cap 💖

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✨ SYNOPSIS ✨

#include <stdcountof.h>

size_t countof(array);

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💫 DESCRIPTION 💫

okay so, this operator counts the number of elements in an array. that's the whole vibe. it's giving "how many of u are there" and the array is like "this many" ✨

BUT — and this is the important part, bestie — if the operand is not an array, it produces a compilation error. not a warning, not a little suggestion, a full on compilation error 💀. the compiler said "no ❤️". so don't try it with a pointer, iykyk.

there's also a keyword, _Countof(), that behaves identically, and can be used without including <stdcountof.h>. same energy, no include needed, she's self-sufficient 👑

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🎀 RETURN VALUE 🎀

The number of elements in the array. that's it. that's the tea 🍓

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👑 STANDARDS 👑

C2y. periodt.

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🦋 HISTORY 🦋

she didn't come from nowhere bestie, she's been making moves:

• gcc 16
• clang 21
• gnulib 202507

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🌈 SEE ALSO 🌈

operator(7) — go read it, it's giving lore 💜

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fr fr, remember: arrays only. anything else and the compiler will humble you 😭

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signing off with love from the Linux man-pages 6.20, dated 2026-02-10 💖✨🎀