Function help with a program

[aaronf89]

I'm having trouble with a function, I have the following function written but it's popping up with errors. The two errors are that largeandsmall is popping up as undefined even though I have it defined in the program, and the first curly brace is popping up with a declaration error. this is all the code I have written including the function

#include <iostream>
#include <string>

using namespace std;

int main()
{
	//Declaration Block
	void largeandsmall(int x, int y);
	int firstNum;
	int secondNum;

	//User Input Block
	cout << "Please enter a number: ";
	cin >> firstNum;

	cout << "Please enter a second number: ";
	cin >> secondNum;

		//Processing Block
		if (firstNum == secondNum)
		{
			cout << "The two numbers are equal ";
		}
		else 
			if (firstNum >= secondNum)
			{ 
				cout << "The first number " << firstNum << "was larger than the second number " << secondNum << endl;
			}
			else 
				if (secondNum >= firstNum)
				{
					cout << "The second number " << secondNum << "was larger than the first number " << firstNum << endl;
				}

		system("pause");
		return 0;
}

void largeandsmall(int x, int y);
{
	if (firstNum == secondNum)
	{
		cout << "The two numbers are equal ";
	}
	else if (firstNum > secondNum)
	{
		cout << "The first number " << firstNum << "was larger than the second number " << secondNum << endl;
	}
	else
	{
		cout << "The second number " << secondNum << "was larger than the first number " << firstNum << endl;
	}
}

[EtDecius]

Line 9: void largeandsmall(int x, int y);

The function prototype (aka forward declaration) should be placed outside of main(). Functions may not be declared within another function.

[aaronf89]

I fixed it but I'm still getting the same errors that I listed above

[48T7M4Gy]

Make these changes:

void largeandsmall(int x, int y) ///<=======
{
    int firstNum = x; ///<=======
    int secondNum = y; ///<======= 

[EtDecius]

Tried compiling and got an error from Line 40. Try removing the semicolon at the end of the line.

void largeandsmall(int x, int y)
{ 
...
}

Once you've done that, you'll probably get new errors saying that firstNum and secondNum are not defined. You'll want to update any use of firstNum and secondNum in the largeandsmall() function to x and y respectively. This will ensure that variables used in largeandsmall() match the arguments you passed.

Also, since largeandsmall() is basically the same as the "Processing Block" in main(), you can delete the Processing Block and simply call your function instead.

largeandsmall(firstNum, secondNum);

system("pause");
return 0;

[Chervil]

Line 40:

void largeandsmall(int x, int y);

remove the semicolon from the end of the line.

Lines 42 to 52. The variables firstNum and secondNum should have the same names as the function parameters x and y. The actual name doesn't matter, but they must be consistent throughout the function.

Lines 20 through 34 - this is duplicating the processing done by the function. Delete this block of code and replace it with a function call:

    largeandsmall(firstNum, secondNum);

edit: sorry - my answer duplicates what has already been said.

[48T7M4Gy]

@OP Better still get rid of a bit of the unnecessary repetition and the semiolon blooper and it should be clearer how a function works. (const just means read-only, ie the function doesn't change the values passed to it.

#include <iostream>
#include <string>

using namespace std;

//Declaration Block
void largeandsmall(const int, const int);

int main()
{
    int firstNum;
    int secondNum;
    
    //User Input Block
    cout << "Please enter a number: ";
    cin >> firstNum;
    
    cout << "Please enter a second number: ";
    cin >> secondNum;
    
    largeandsmall(firstNum, secondNum);
    
    return 0;
}

void largeandsmall(const int x, const int y) ///<=======
{
    if (x == y)
    {
        cout << "The two numbers are equal ";
    }
    else if (x > y)
    {
        cout << "The first number " << x << "was larger than the second number " << y << endl;
    }
    else
    {
        cout << "The second number " << x << "was larger than the first number " << y << endl;
    }
}

[aaronf89]

@Kemort I have to include the else if statements in the main of the program it's a requirement for the assignment I'm working on

[48T7M4Gy]

@OP OK go for it Cheers :)

[aaronf89]

i'm also now having a problem with my program when it compiles it displays everything twice I have the following code:

#include <iostream>
#include <string>

using namespace std;

void largeandsmall(const int, const int);

int main()
{
	//Declaration Block
	int firstNum;
	int secondNum;

	//User Input Block
	cout << "Please enter a number: ";
	cin >> firstNum;

	cout << "Please enter a second number: ";
	cin >> secondNum;

	largeandsmall(firstNum, secondNum);

	//Processing Block
	if (firstNum == secondNum)
	{
		cout << "The two numbers are equal ";
	}
	else 
		if (firstNum >= secondNum)
		{
			cout << "The first number " << firstNum << "was larger than the second number " << secondNum << endl;
		}
		else 
			if (secondNum >= firstNum)
			{
				cout << "The second number " << secondNum << " was larger than the first number " << firstNum << endl;
			}

	system("pause");

	return 0;
}

void largeandsmall(int x, int y)
{
	if (x == y)
	{
		cout << "The two numbers are equal ";
	}
	else 
		if (x > y)
	{
		cout << "The first number " << x << "was larger than the second number " << y;
	}
	else
		if (y > x)
	{
		cout << "The second number " << x << "was larger than the first number " << y;
	}
}

[48T7M4Gy]

It displays everything twice because you have two sets of if statements, one in main and the other in the function.

Comment out your line 21 and one set of output should be eliminated.

[48T7M4Gy]

BTW I changed my line 26 by adding the two keywords 'const'.

[Enoizat]

it displays everything twice

Shouldn’t it?
Let’s assume the user gives the following two numbers: 1 and 2. What do you expect your code to do?
On line 21 it will pass the two numbers to the function largeandsmall(), which will display which one is larger and which is smaller; later, in the rows 24-37, the code again evaluates if the numbers are equal or one is larger and prints out which one is larger and which is smaller.

I think you can easily work out a solution for this ‘issue’ by yourself, can’t you?

- - -
Edit: sorry, hadn't seen kemort already answered.

[aaronf89]

@Kemort sorry to sound dumb but what do you mean by comment out line 21?

@Enoizat I'm still learning most everything on this subject so I do have a little troube with some things

[48T7M4Gy]

Just delete the line and see what happens :)

[48T7M4Gy]

To comment out a line you put // at the start of the line. That way the compiler will ignore the line. (Deleting the line means you have to type it back in. By commenting the line with // all you have to do is delete the // to get the line recognised by the compiler again)

[aaronf89]

thing is I also need to call the function to the program as well so deleting that would get rid of calling the function altogether

[48T7M4Gy]

So delete the other part which is what I showed you in my earlier post. But then you said you had to keep both.

You'll have to decide what you want. You can't have both.