conditions for function overloading in c++ code example

Example: c++ function overload

/*A function over load in c++ is when you take a function with the same definition but change the input variables.
  This can include multiple functions with the same name see below
  */
#include <iostream>
using namespace std;

int function1(int var1){//example of single variable
	//do somthing
}
int function1(int var1,int var2){//of overload
	//do somthing	
}
int function1(int var1,string var3){//of overload
	//do somthing	
}

int main(){
 
  cout << "Hello World" << endl;
  function1(4);
  function1(3,-90);
  function1(34,"it works");//these should all work even tho they have different input variables
  return 0;
}