How is my code ? calculator c++

[danielcplusplus]

Hey, i started learning C++ week ago, and having fun , anyway i wrote a simple C++ Calculator it works ^^, just wondering, how is my c++ code ? i mean from a professional perspective..
this is how it looks: Gyazo - ac0f873000fd200013e860f00873fec1.png

// DECLARATIONS ---------------------------
#include <iostream>
#include <string>
#include <conio.h>
#include <fstream>
// FUNCTION DECLARATIONS ------------------
bool DRAW_INTERFACE();
int math();
// MAIN FUNCTION --------------------------
int main() {
    if (!DRAW_INTERFACE()) return 0;
    _getch();
    math();
    return 0;
    std::cin.get();
    system("pause");
}
// DRAW INTERFACE -------------------------
bool DRAW_INTERFACE() {
    std::cout<<"Checking INTERACE.TXT... ";
    std::ifstream FILE("INTERFACE.TXT");
    if (!FILE.good()) {
        std::cout<<"ERROR: FILE NOT FOUND.";
        return false;
    }
    else {
        system("cls");
        while (!FILE.eof()) {
            std::string FILE_LINE;
            std::getline(FILE, FILE_LINE);
            std::cout<<FILE_LINE<<std::endl;
        }
    }
    return true;
}
// MATH OPERATION -------------------------
int math() {
    float a, b, result;
    char operation;
    std::cin >> a >> operation >> b;
    switch (operation) {
        case '+' :
            result = a + b;
            break;
        case '-' :
            result = a - b;
            break;
        case '*' :
            result = a * b;
            break;
        case '/' :
            result = a / b;
            break;
        default :
            std::cout << "Try entering an exercise for example( 16 * 16 )" << std::endl;
    }
    std::cout<<"Your answer is: "<<result<<std::endl;


    system("pause");
    return true;
}

[whiteflags]

I think you should just make the header part of the program data. You won't lose it this way.

#include <iostream>
#include <iomanip>

using namespace std;

void DrawInterface()
{
    static const char *FancyHeader = 
    "_________        .__               .__          __                \n"
    "\\_   ___ \\_____  |  |   ____  __ __|  | _____ _/  |_  ___________ \n"
    "/    \\  \\/\\__  \\ |  | _/ ___\\|  |  \\  | \\__  \\\\   __\\/  _ \\_  __ \\\n"
    "\\     \\____/ __ \\|  |_\\  \\___|  |  /  |__/ __ \\|  | (  <_> )  | \\/\n"
    " \\______  (____  /____/\\___  >____/|____(____  /__|  \\____/|__|   \n"
    "        \\/     \\/          \\/                \\/                  \n"
    ;
    static const char *Version = "v1.0";
    static const char *Author = "Daniel";
    cout<<FancyHeader<<'\n'<<"Calculator "<<Version<<" - Coded by: "<<Author<<'\n';
    cout<<setfill('_')<<setw(79)<<'\n';     // line
    cout<<setfill(' ');                     // back to normal
}

This function works. I will admit it is easier to dump that stuff into a file but it isn't too hard to encode as a string. Just remember to replace every backslash with \\. You can do that with a global search and replace.

As for the rest of the code:

Code written after a return statement will not be executed. Your compiler output should tell you about this.

Be careful what you name things. I think your convention is confusing. Nothing you capitalized is a constant. FILE is a word already in use by the stdio library. FILE_LINE is dangerously close to __FILE__ and __LINE__ that are already defined.

Do not ask for text input without some sort of prompt.

Effort should be spent on how the program recovers when the user sends bad input. Imagine a user writes his algebra homework, or maybe "one plus two"! Consider how this FAQ applies here.

Finally, I'm not convinced you need to use conio at all. system("pause"); isn't a great function but it will do what you are asking _getch() to do.

[danielcplusplus]

Huge thanks for your feedback, i didn't quite understood when you said: "Code written after a return statement will not be executed." what do you mean

[whiteflags]

Look at your main() function again. On line 14, you return 0. This ends the function, so the two lines after that will not be reached.

[jaxdid]

I'm a newbie but well done. Prior programming experience outside of c++?

[danielcplusplus]

Java, web development..