C++ If Statements Help

Hello,

My name is MP and I am new to C++. I am trying to create a project and am having no luck.

I am trying to finish a assignment, but I am baffled. The assignment is to Write a program that reads in three integers and determines and prints the middle number numerically in the group. The values are NOT necessarily entered in numeric order. Also compound if statements and nested if statements are not needed or allowed).

Here is the code I wrote, but keep getting the 3 error C2059: syntax error : 'if'.

Code:

---


// Three integers printing middle interger numberically: 1/14/2008, 2:05PM

//

#include <iostream> // allows program to output data to the screen

#include "Rhod_2a.h"

using std::cout; // program uses cout

using std::cin; // program uses cin

using std::endl; // program uses endl

// function main begins program execution

int main()

{

int number1; // first integer to compare

int number2; // second integer to compare

int number3; // third integer to compare

cout << "Enter three integers: "; //prompt user for data

cin >> number1 >> number2 >> number3; // read three integers from user


if ( number1 <= number2 )

cout << number1 <<

if (number2 < number1 )

cout << number2 <<

if ( number3 < number1 )

cout << number3 << endl;

if ( number1 > number2 )

cout << number1 <<

if ( number2 > number1 )

cout << number 2 <<

if ( number2 < number3 )

cout << number2 <<

if ( number3 <= number2 )

cout << number3 << endl;

if ( number1 > number2 )

cout << number1 <<

if ( number1 > number3 )

cout << number1 <<

if ( number2 > number1 )

cout << number2 <<

if ( number2 > number3 )

cout << number2 <<

if ( number3 > number1 )

cout << number3 <<

if ( number3 > number2 )// number3 is greater than number2

cout << number3 << endl;

return 0; // indicate that program ended successfully

} //end function main

 

Errors:

------ Build started: Project: Rhod_2a, Configuration: Debug Win32 ------

Compiling...

Rhod_2a.cpp

c:\documents and settings\.your-jz14f3vb7a\my documents\visual studio 2005\projects\rhod_2a\rhod_2a\rhod_2a.h(33) : error C2059: syntax error : 'if'

c:\documents and settings\.your-jz14f3vb7a\my documents\visual studio 2005\projects\rhod_2a\rhod_2a\rhod_2a.h(42) : error C2059: syntax error : 'if'

c:\documents and settings\.your-jz14f3vb7a\my documents\visual studio 2005\projects\rhod_2a\rhod_2a\rhod_2a.h(54) : error C2059: syntax error : 'if'

Build log was saved at "file://c:\Documents and Settings\.YOUR-JZ14F3VB7A\My Documents\Visual Studio 2005\Projects\Rhod_2a\Rhod_2a\Debug\BuildLog.htm"

Rhod_2a - 3 error(s), 0 warning(s)

========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

---

Yes, the compiler doesn't see the end of your first if-statement before it finds the next if-statement. Each if-statement should end with a semicolon.

--
Mats

PS Also am I correct in this coding? I would really like direction?

Good to see that you posted your code in code tags, but kindly indent your code properly.

The problem is just that you have repeated the line:

Code:

---

cout << number1 <<

---

The above is clearly a syntax error, and the compiler interprets it as:

Code:

---

cout << number1 << if

---

and thus informs you that the if keyword is out of place here.

Your code also doesn't quite do what you are asked to do - first of all, you have far to many "cout << ..." statements.

You need to use some sort of if-statement that splits the high and low parts away from the "middle". I would probably write it using a variable called "middle". I'm not going to show you how to do that just yet, because I think you need to learn from experience, not from reading what others have done.

--
Mats

Code:

---


// Three integers printing middle interger numberically: 1/14/2008, 2:05PM

//

#include <iostream> // allows program to output data to the screen
#include "Rhod_2a.h"
using std::cout; // program uses cout
using std::cin; // program uses cin
using std::endl; // program uses endl

// function main begins program execution
int main()
{
        int number1; // first integer to compare
        int number2; // second integer to compare
        int number3; // third integer to compare

        cout << "Enter three integers: "; //prompt user for data
        cin >> number1 >> number2 >> number3; // read three integers from user

        if ( number1 <= number2 )
        cout << number1 << if (number2 < number1 )
                cout << number2 << if ( number3 < number1 )
                        cout << number3 << endl;
        if ( number1 > number2 )
                cout << number1 << if ( number2 > number1 )
                        cout << number 2 << if ( number2 < number3 )
                                cout << number2 << if ( number3 <= number2 )
                                        cout << number3 << endl;
        if ( number1 > number2 )
                cout << number1 << if ( number1 > number3 )
                        cout << number1 << if ( number2 > number1 )
                                cout << number2 << if ( number2 > number3 )
                                        cout << number2 << if ( number3 > number1 )
                                                cout << number3 <<  if ( number3 > number2 )
                                                        cout << number3 << endl;
        return 0; // indicate that program ended successfully
} //end function main

---

This is what it would look like if you indented properly.
And Visual Studio indents for you, so why not just accept the default indentation it uses instead of making a mess of everything?
As I can see, there's plenty of errors. It's illegal to output an if! Not to mention the program doesn't make sense.

Approach it like this.

First, name your variables something like:

int low, middle, high ;

Then, have a temporary int that lets you swap values:

int temp ;

Then, get your numbers like you are. That's good.

Then, do the compares. For instance, if low is higher than middle, swap the two. Then, if low is higher than high, swap them as well. Now you are done with low, move on to middle. When you are done with middle, variable high has already taken care of itself.

Todd

Thanks for your kindness and patience with this novice! I retried the coding, still with the incorrect results. I get 3 warnings and the middle value does not present itself. Could you please review and steer me in the direction I need to be?

Code:

---

#include <iostream> // allows

using std::cout;
using std::cin;
using std::endl;

int main ()
{
        int number1, number2, number3, middle;
        cout << "Enter three numbers.\n";
        cout << "First: ";
        cin >> number1;
        cout << "\nSecond: ";
        cin >> number2;
        cout << "\nThird: ";
        cin >> number3;
        cout << "\n";

        if (number2 < number1 < number3)
                middle = number1; if (number1 < number2 < number3)
                        middle = number2; if (number1 < number3 < number2)
                                middle = number3;

        cout << "Middle: " << middle;
        cout << "\n";

                return 0;
}

----- Build started: Project: Rhod_2, Configuration: Debug Win32 ------
Compiling...
Rhod_2.cpp
c:\documents and settings\mary pat rhodes.your-jz14f3vb7a\my documents\visual studio 2008\projects\rhod_2\rhod_2\rhod_2.h(29) : warning C4804: '<' : unsafe use of type 'bool' in operation
c:\documents and settings\mary pat rhodes.your-jz14f3vb7a\my documents\visual studio 2008\projects\rhod_2\rhod_2\rhod_2.h(30) : warning C4804: '<' : unsafe use of type 'bool' in operation
c:\documents and settings\mary pat rhodes.your-jz14f3vb7a\my documents\visual studio 2008\projects\rhod_2\rhod_2\rhod_2.h(31) : warning C4804: '<' : unsafe use of type 'bool' in operation
Linking...
Embedding manifest...
Build log was saved at "file://c:\Documents and Settings\Mary Pat Rhodes.YOUR-JZ14F3VB7A\My Documents\Visual Studio 2008\Projects\Rhod_2\Rhod_2\Debug\BuildLog.htm"
Rhod_2 - 0 error(s), 3 warning(s)
========== Build: 1 succeeded, 0 failed, 0 up-to-date, 0 skipped ==========

---

Cheers,
Mary Pat

Code:

---

#include <iostream> // allows

using std::cout;
using std::cin;
using std::endl;

int main ()
{
        int number1, number2, number3, middle;
        cout << "Enter three numbers.\n";
        cout << "First: ";
        cin >> number1;
        cout << "\nSecond: ";
        cin >> number2;
        cout << "\nThird: ";
        cin >> number3;
        cout << "\n";

        if (number2 < number1 < number3)
                middle = number1;
        if (number1 < number2 < number3)
                middle = number2;
        if (number1 < number3 < number2)
                middle = number3;

        cout << "Middle: " << middle;
        cout << "\n";

        return 0;
}

---

Come on. Visual Studio indents for you. Let it indent for you and don't place more than one statement on the same line.
This is not a coding problem; it's a logic problem. Think! How would you do this in real life, given 3 numbers and print them in order from smallest to biggest?

Hey Mary Pat.

Code:

---

        if (number2 < number1 < number3)
                middle = number1; if (number1 < number2 < number3)
                        middle = number2; if (number1 < number3 < number2)
                                middle = number3;

---

You can't code like this - it's not valid syntax. How that reads is:

if number2 is less than number1 is less than number 3 ...

Stick with one condition inside the parens for now until you gain more experience.

Try something like this:

Code:

---

int temp ;
if (low > middle) {
  temp = low ;
  low = middle ;
  middle = temp
}

---

And then do the same thing with low and high (or number"x" and number"y"). Then, do middle and high.

Todd

Here is the code so far

Code:

---

// List Middle Value Integer Out of Three ; Mary Pat Rhodes; Jan. 17, 2008; 1:54 PM
//
#include <iostream> // allows

using std::cout;
using std::cin;
using std::endl;

int main ()
{
        int number1, number2, number3, middle;
        cout << "Enter three numbers.\n";
        cout << "First: ";
        cin >> number1;
        cout << "\nSecond: ";
        cin >> number2;
        cout << "\nThird: ";
        cin >> number3;
        cout << "\n";

        if (number1 > number2)
                if (number1 < number3)
                middle = number1;

        if (number1 < number2)
                if(number2 < number3)
                middle = number2;

        if (number1 < number3)
                if(number3 < number2)
                middle = number3;

        cout << "Middle: " << middle;
        cout << "\n";

                return 0;
}

---

But i getting a debugging error that has me really baffled!

Code:

---

'Rhod_2a.exe': Loaded 'C:\Documents and Settings\Mary Pat Rhodes.YOUR-JZ14F3VB7A\My Documents\Visual Studio 2005\Projects\Rhod_2a\debug\Rhod_2a.exe', Symbols loaded.
'Rhod_2a.exe': Loaded 'C:\WINDOWS\system32\ntdll.dll', No symbols loaded.
'Rhod_2a.exe': Loaded 'C:\WINDOWS\system32\kernel32.dll', No symbols loaded.
'Rhod_2a.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC80.DebugCRT_1fc8b3b9a1e18e3b_8.0.50727.42_x-ww_f75eb16c\msvcp80d.dll', No symbols loaded.
'Rhod_2a.exe': Loaded 'C:\WINDOWS\WinSxS\x86_Microsoft.VC80.DebugCRT_1fc8b3b9a1e18e3b_8.0.50727.42_x-ww_f75eb16c\msvcr80d.dll', No symbols loaded.
'Rhod_2a.exe': Loaded 'C:\WINDOWS\system32\msvcrt.dll', No symbols loaded.
Run-Time Check Failure #3 - The variable 'middle' is being used without being defined.
The program '[3584] Rhod_2a.exe: Native' has exited with code 0 (0x0).

---

Where, what, how do I clear this error??

Thanks again for all your patience and kindness.

Cheers,
MP

Code:

---

if (number1 > number2)
        if (number1 < number3)
                middle = number1;

---

Look out. I detect something that is called a nested if in your code and your requirements say that they are not allowed.

I think Todd has given you some important hints.

I think your runtime check has detected that the variable middle was never set, or could not ever get set, and thusly, you'll be using an uninitialized value in the COUT.

Consider the case when the user enters 3, 3 and 3 - none of your IF conditions will be met.

Todd

Are you listening?

Quote:

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Originally Posted by Elysia

Come on. Visual Studio indents for you. Let it indent for you and don't place more than one statement on the same line.

---

Is there a reason you're changing the default indentation Visual Studio uses for you?

Todd,

I am sorry to have bothered you. I am just not getting what you are saying. Should I be putting "=" signs in too? Maybe "<="?

I am trying to get the info you are providing, but I am letting the rude comments of Elysia interfer.

Thanks again,
Mary Pat

Quote:

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Originally Posted by moporho

Todd,

I am sorry to have bothered you. I am just not getting what you are saying. Should I be putting "=" signs in too? Maybe "<="?

---

Perhaps, but initializing "middle" to (any) one of the input values should work fine too

Quote:

---

I am trying to get the info you are providing, but I am letting the rude comments of Elysia interfer.

Thanks again,
Mary Pat

---

I know it may sound like Elysia is rude [he/she may even BE rude], but correctly indenting the code is part of writing good code, so you should really try to understand:
How to make the editor indent the code correctly and/or why the code doesn't look correct when you post it here.

The reason indentation is important is that it's showing how the if-statements relate to the actual code.

Also, I don't actually think you need if-statements "inside each other" (nested if's) to solve this problem.

--
Mats

Quote:

---

Originally Posted by moporho

I am trying to get the info you are providing, but I am letting the rude comments of Elysia interfer.

---

Then maybe I should retort that you are rude to ignore everything I've written thus far, not even a single acknowledgment even that you saw what I wrote but want to focus on something else first.
Indentation is a very important thing because it makes your code readable.

Elysia has a lot to offer us all. If Elysia's comments are annoying you, take with 1 grain of salt. :)

You do have a nested IF going on there.

I'm going to simplify the logic. You don't need to have all the variables sorted, just just need to find the middle value.

This logic will work. See if you can implement this logic:

if number1 is less than than or equal to number2 AND number2 is less than or equal to number3 then number2 is the middle number.

else if number2 is less than than or equal to number1 AND number1 is less than or equal to number3 then number1 is the middle number.

else number3 is the middle number.

Todd

Quote:

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Originally Posted by Todd Burch

This logic will work. See if you can implement this logic:

if number1 is less than than or equal to number2 AND number2 is less than or equal to number3 then number2 is the middle number.

else if number2 is less than than or equal to number1 AND number1 is less than or equal to number3 then number1 is the middle number.

else number3 is the middle number.

Todd

---

This logic won't work. (Consider number1 = 9, number2 = 7, and number3 = 5.) But the idea is right: to be the middle number, you have to have one number greater and one number less. You need to add the symmetric cases as well (that is for example, number2 is the middle number if either number1 <= number2 <= number3, as given above, or number3 <= number2 <= number1).

Quote:

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Originally Posted by tabstop

This logic won't work.

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Oops. You're rightll sorry MP.

Quote:

---

(that is for example, number2 is the middle number if either number1 <= number2 <= number3, as given above, or number3 <= number2 <= number1).

---

MP, don't interpret this that number1 <= number2 <= number3 is valid C syntax for what you want to do - you had that before, and while we can all visualize and understand what it means, it's not code you want to implement verbatim.

Todd