This article will examine entry points in C# programs, and the possible errors you can come across. The function to be called in any C# program is Main. We can have as many as four different ways to declare Main in our program. They are as follows:

static void Main() {...}
static int Main() {...}
static void Main(string[] a) {...}
static int Main(string[] args) {...}

The operating system calls Main and waits for it to return a value. This value denotes the success or failure of the program.

Main can either return a number or result in no return value, that is, void. If it returns an int, by convention, a value of zero means success and any other value indicates an error. No international authority can standardize the error numbers, it largely depends on the programmer himself.