Question

Is there any difference between, for example

int array[]={1, 2, 3, 4, 5};

and,

int array[5]={1, 2, 3, 4, 5};

Compiler needs to calculate number of elements by self for the first case, and that can take a some time ({...} of 1234332534 elements), so second case is efficient than the first?

Answer 1

There’s no difference, as long as the explicit element count between [] is the same as the number of initializers between the {}.

The question about “efficiency” is moot. The array size is determined at compile time, which means it has no impact on the efficiency of the code. And since in any case the compiler will have to parse the initializer list anyway, it has no real impact on the efficiency of the compilation.