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c++variable-length-arraygcc-extensionsclang-extensions

Are variable length arrays there in c++?

I had always thought that variable length arrays were not allowed in c++(Refer :Why aren't variable-length arrays part of the C++ standard?) .But than why does this code compile and work?

#include <iostream>
using namespace std;

int main () {

    int n;
    cin >> n;

    int a[n];

    for (int i=0; i<n; i++) {
        a[i] = i;
    }

    for (int i=0; i<n; i++) {
        cout << a[i] << endl;
    }
}
Solution

  • The current C++ standard does not require that compilers support VLAs. However, compiler vendors are permitted to support VLAs as an extension. GCC >= 4.7, for example, does.

    It was originally proposed that VLAs would appear in C++14, however the proposal did not succeed. They also, ultimately, did not appear in C++17.