Int subtraction from a string

Question

Why doesn't the code below give an error that says the array is out of range?

#include <iostream>

int main() {
    std::cout << "Hello, world!" - 50;
    return 0;
}

Answer 1

Why the code below does not give the error that array is out of range?

Because "Hello, world!" is a string literal of type const char[14]that decays to a pointer(const char*) due to type decay.

Thus effectively, you're subtracting 50 from that resulting(decayed) pointer. And when operator<< dereferences this pointer, it will lead to undefined behavior.

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Note that undefined behavior means anything can happen including but not limited to the program giving your expected output. But never rely on the output of a program that has UB. The program may just crash