For example, I have an array with 3 elements
int array [] = {1, 4, 66};
How can I know how many elements array contains?
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normanius
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1In `c++17` you have [https://en.cppreference.com/w/cpp/iterator/size](https://en.cppreference.com/w/cpp/iterator/size) – drescherjm Nov 29 '19 at 17:36
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https://stackoverflow.com/questions/4108313/how-do-i-find-the-length-of-an-array – Alireza Abbasi Nov 29 '19 at 17:37
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The whole answer is in Below link: https://stackoverflow.com/questions/4108313/how-do-i-find-the-length-of-an-array – Alireza Abbasi Nov 29 '19 at 17:39
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1Use `std::array` or `std::vector` and call the `.size()` member function. Forget that C-style arrays exist and don't ever use them. – Jesper Juhl Nov 29 '19 at 18:01
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Do this with:
std::size(myarray);
std::size is in <iterator>.
Some sources will tell you to use a "trick" like sizeof(myarray)/sizeof(myarray[0]). But this is error-prone. The name of an array decays really easily to a pointer, for which this "trick" gives the wrong result. std::size will either work, or break the build.
Plus, when you switch from C arrays to std::array, it'll still work!
Lightness Races in Orbit
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1In case they don't have c++17 `template
std::size_t size(const T(&)[N]) { return N; }` – NathanOliver Nov 29 '19 at 17:47 -
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You can use sizeof(myarray)/sizeof(int).
But you really should start using std::array, which does the same thing as your array and is safer. And comes with a size() method.
Paul92
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