C++ Getting an error with my functions

Question

Need some homework help. I'm new to C++, and I'm getting an error I don't understand. Here's my code:

/*
 * homework6.cpp
 * Coder: omega9380
 * Final Project
 */

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int main () {

    void welcomeScreen();
    void printLine( int length );

    welcomeScreen();

    return 0;
}

void welcomeScreen() {
    string userName = "";
    string title1 = "CMPSC101 FINAL PROJECT";
    string title2 = "CREATED BY: OMEGA9380";

    // Welcome screen:

    system("CLS");

    cout << "/";
    printLine(80);
    cout << "\\" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "|" << setw(41 + (title1.length() / 2)) << title1 << setw(40 - (title1.length() / 2)) << "|" << endl;
    cout << "|" << setw(41 + (title2.length() / 2)) << title2 << setw(40 - (title2.length() / 2)) << "|" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "\\";
    printLine(80);
    cout << "/" << endl;
}

void printLine( int length ) {
    for ( int i = 0; i < length; i++ ) {
        cout << "=";
    }
}

The error is "error: 'printLine' was not declared in this scope". I did declare "printLine()" in the main() function, isn't that enough? Or do I need to declare the function name in every function I plan to use it in? And to answer the burning question, I have to use functions in this final project. Thanks!!!

Easier to declare your functions outside any other functions. — aschepler, Apr 10 '17 at 20:26
The key is "in this scope" `void printLine( int length );` is declared inside `main`, so it is only visible inside `main`'s scope. — user4581301, Apr 10 '17 at 20:27

Marek Chocholáček · Accepted Answer · 2017-04-11T22:56:30.297

3

Assuming you don't really want to have functions declared in main you either need to forward declare welcomeScreen and printLine functions:

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int printLine(int);
void welcomeScreen();

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

void welcomeScreen() {
    // definition
}

void printLine(int length) {
    // definition
}

or just define them before main:

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

int printLine(int length) {
    //definition
}

void welcomeScreen() {
    // definition
}

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

edited Apr 11 '17 at 22:56

answered Apr 10 '17 at 20:32

Marek Chocholáček

542
2
6

That fixed it. I didn't realize that you could declare variables and functions outside of main(). Thanks!! – Jeremy Kellogg Apr 11 '17 at 22:33
@JeremyKellogg of course you can! You are welcome friend, if you have any question feel free to contact me, I'll gladly help. – Marek Chocholáček Apr 11 '17 at 22:54

score 2 · Answer 2 · answered Apr 10 '17 at 20:37

Your printLine function is only declared in main, so the welcomeScreen function can't see it.

You should move your welcomeScreen and printLine functions before main, and make sure printLine is before welcomeScreen, so that welcomeScreen knows it exists before you try to call it.

Like this:

/*
 * homework6.cpp
 * Coder: omega9380
 * Final Project
 */

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

void printLine( int length ) {
    for ( int i = 0; i < length; i++ ) {
        cout << "=";
    }
}

void welcomeScreen(void) {
    string userName = "";
    string title1 = "CMPSC101 FINAL PROJECT";
    string title2 = "CREATED BY: OMEGA9380";

    // Welcome screen:

    system("CLS");

    cout << "/";
    printLine(80);
    cout << "\\" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "|" << setw(41 + (title1.length() / 2)) << title1 << setw(40 - (title1.length() / 2)) << "|" << endl;
    cout << "|" << setw(41 + (title2.length() / 2)) << title2 << setw(40 - (title2.length() / 2)) << "|" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "\\";
    printLine(80);
    cout << "/" << endl;
}

int main () {

    welcomeScreen();

    return 0;
}

Rogus · Answer 3 · 2017-04-10T20:29:46.770

1

You are declaring the printLine() function inside the scope of main() function. This declaration is not seen by the definition of welcomeScreen().

Move the declaration of printLine outside of main and before welcomeScreen

The same should be done with the declaration of welcomeScreen

edited Apr 10 '17 at 20:29

answered Apr 10 '17 at 20:26

Rogus

750
5
11

Your answer was and is correct. It just had room for improvement. I have no idea why it got downvoted. – user4581301 Apr 10 '17 at 20:32
me neither, but what can you do :) i see that anyone who answers this question gets downvoted – Rogus Apr 10 '17 at 20:33
here have an up, You've put effort into answering and got down voted lul. Guess it didn't satisfy OP or something. – Marek Chocholáček Apr 10 '17 at 20:47

score -1 · Answer 4 · edited Apr 10 '17 at 20:28

You don`t have declarations for your functions, so use it like this:

/*
 * homework6.cpp
 * Coder: omega9380
 * Final Project
 */

#include <iostream>
#include <string>
#include <iomanip>
using namespace std;

void welcomeScreen() {
    string userName = "";
    string title1 = "CMPSC101 FINAL PROJECT";
    string title2 = "CREATED BY: OMEGA9380";

    // Welcome screen:

    system("CLS");

    cout << "/";
    printLine(80);
    cout << "\\" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "|" << setw(41 + (title1.length() / 2)) << title1 << setw(40 - (title1.length() / 2)) << "|" << endl;
    cout << "|" << setw(41 + (title2.length() / 2)) << title2 << setw(40 - (title2.length() / 2)) << "|" << endl;
    cout << "|" << setw(81) << "|" << endl;
    cout << "\\";
    printLine(80);
    cout << "/" << endl;
}

void printLine( int length ) {
    for ( int i = 0; i < length; i++ ) {
        cout << "=";
    }
}

int main () {

    void welcomeScreen();
    void printLine( int length );

    welcomeScreen();

    return 0;
}

Help someone to get -1, you people are unbelievable. – Mecanik Apr 11 '17 at 08:34 — Mecanik, Apr 11 '17 at 08:34

C++ Getting an error with my functions

4 Answers4