C++ static local function vs global function

Question

What is the utility of having static functions in a file ?

How are they different from having global functions in a file ?

static int Square(int i)
{
            


        

Answer 1

A static function simply means that the linker cannot export the function (i.e. make it visible to other translation units). It makes the function "private" to the current translation unit. It is the same as wrapping the function in an anonymous namespace.

namespace {

    int Square(int i)
    {
       return i * i;
    } 

}

Generally, using an anonymous namespace is the preferred C++ way of achieving this, instead of using the static keyword.