What is the first function executed in a C plus plus program?

Answer 1

For gcc there's a non-standard solution. Declare the function with __attribute__((constructor)) (note the double parentheses).

Like this:

void init(void) __attribute__ ((constructor));

void init(void) {

// your code goes here

}

Starting with gcc 4.3 there's even a possibility to assign a priority to the "constructor". See http://gcc.gnu.org/onlinedocs/gcc-4.3.0/gcc/Function-Attributes.html for details.

Answer 2

main()

Technically, the first function executed is the library entry point, but that does not count from a programmer's perspective.