Strange errors

[nafiz12345]

This is the first c++ scripting i have ever done, but there was an error that i don't know how to fix.
The following error is:
-error LNK2019: unresolved external symbol _main referenced in function _tmainCRTStartup
-error LNK1120: 1 unresolved externals

#include <iostream>
#include <stdlib.h>

void Console_test()
{
	char colour;
    std::cout << "Hello user" << ",/0" << "What is your favorite colour" << "green," << "blue/0" << "or red?/n";
	std::cin >> colour;
	switch (colour)
	{
	case 1: system("COLOR 2");
		break;
	case 2: system("COLOR 1");
		break;
	case 3: system("COLOR 4");
		break;
	default: system("COLOR F0");
		break;
	};
	if (colour == 1 && 2 && 3)
	{
		std::cout << "Voila" << "," << "The colour has been switched :D/n";
	};
};

[MiiNiPaa]

You do not have main() function in your program.
Every program should contain int main() as this is the function which started at the program launch.

[nafiz12345]

Tried but still happens, where should i put it exactly?

[MiiNiPaa]

No. Main function in C++ has signature either

int main()
//or
int main(int argc, char** argv)

[Ganado]

A few problems: As MiiNiPaa pointed out, you need an int main() { /*code here*/ } function where your code execution begins.
for example:

int main()
{
    Console_test();
    return 0;
}

___________________
Line 20:
if (colour == 1 && 2 && 3)
The && operator here isn't working in the way you want it to. 2 and 3 are treated as their own separate expressions. Also, I think you mean to use OR logic instead of AND, because you want that if-statement to execute if any of the options are true.

so basically:
if (colour == 1 || colour == 2 || colour == 3)
__________________
Line 7: The escape character for "newline" is '\n' not '/n'.

[nafiz12345]

Oh thanks.