Newbie With C++, Need Help

[Tuxiscool]

Ok, i have *tried* to make a calculator for one of my first programs and i get a few errors on compile, can anyone help me fix these?

 

Here's my code

 

#include <iostream.h>



struct answer{

 int multiply;

 int add;

 int divide;

 int subtract;

}



{

main()



int Choice;

 int mulnumone;

 int mulnumtwo;

int addnumone;

int addnumtwo;

int divnumone;

int divnumtwo;

int subnumone;

int subnumtwo;



while (1) {



 // Menu Heading



 cout << "ttt//////////////////////////n";

 cout << "ttt/////// CALCULATOR ///////n";

 cout << "ttt//////////////////////////n";



 //Menu Choices



 cout << "nttt1) Multiply Numbers n";

 cout << "ttt2) Add Numbers n";

 cout << "ttt3) Divide Numbers n";

 cout << "ttt4) Subtract Numbers n";

 cout << "ttt5) Exit the calculator n";

 cout << "ntttPlease Enter your choice:  ";



 // Find users choice



 cin >> Choice;



 // Accordng to choice Calculate users input



 // Multiplication

 

if (Choice == 1)

   cout << "ntttYou chose to Multiply Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Multiply, after you type each nimber, press enternttt";

 cout << "ntttEnter First Number:  nttt";

 cin >> mulnumone;

 cout << "ntttEnter Second Number:  nttt";

 cin >> mulnumtwo;



 // Calculate the Multiplication Equation



 answer.multiply = mulnumone * mulnumtwo; 

 cout << mulnumone << " times " << mulnumtwo << " equals " << answer.multiply << "n";



 // Addition 



else if (Choice == 2)

   cout << "ntttYou chose to Add Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Add, after you type each nimber, press enternttt";

 cout << "ntttEnter First Number:  nttt";

 cin >> addnumone;

 cout << "ntttEnter Second Number:  nttt";

 cin >> addnumtwo;



 // Calculate the Addition Equation



 answer.add = mulnumone + mulnumtwo;

 cout << addnumone << " plus " << addnumtwo << " equals " << answer.add << "n";



 // Division



else if (Choice == 3)

  cout << "ntttYou chose to Divide Numbers.nttt";

cout << "ntttEnter the numbers that you want to Divide, after you type each nimber, press enternttt";

cout << "ntttEnter First Number:  nttt";

cin >> divnumone;

cout << "ntttEnter Second Number:  nttt";

cin >> divnumtwo;



// Calculate the Division Equation



answer.divide = divnumone / divnumtwo;

cout << divnumone << " divided by " << divnumtwo << " equals " << answer.add << "n";



// Subtraction



else if (Choice == 4)

cout << "ntttYou chose to Subtract Numbers.nttt";

cout << "ntttEnter the numbers that you want to Subtract, after you type each nimber, press enternttt";

cout << "ntttEnter First Number:  nttt";

cin >> subnumone;

cout << "ntttEnter Second Number:  nttt";

cin >> subnumtwo;



//Calculate the Subtraction Equation



answer.subtract = subnumone / subnumtwo;

cout << subnumone << " minus " << subnumtwo << " equals " << answer.subtract << "n";



// If users choice was to exit the calculator, exit



else if (Choice == 5)

  {

    cout << "ntttYou chose to Exit the Calculator. Bye.nttt";

    break;

  }



// If users Choice is not valid, must enter again



else

  {

    cout << "ntttYour choice is NOT valid!n";

    cout << "tttPlease enter a CORRECT choice!nnttt";

  }

}



return 0;

}

 

and here is g++'s output (through emacs)

 

g++ -O2 calculator.cpp -o calculator -Wno-deprecated

calculator.cpp:13: parse error before `{' token

calculator.cpp:26: parse error before `while'

calculator.cpp:31: syntax error before `<<' token

calculator.cpp:32: syntax error before `<<' token

calculator.cpp:36: syntax error before `<<' token

calculator.cpp:37: syntax error before `<<' token

calculator.cpp:38: syntax error before `<<' token

calculator.cpp:39: syntax error before `<<' token

calculator.cpp:40: syntax error before `<<' token

calculator.cpp:41: syntax error before `<<' token

calculator.cpp:45: syntax error before `>>' token

calculator.cpp:53: syntax error before `<<' token

calculator.cpp:54: syntax error before `<<' token

calculator.cpp:55: syntax error before `>>' token

calculator.cpp:56: syntax error before `<<' token

calculator.cpp:57: syntax error before `>>' token

calculator.cpp:62: syntax error before `<<' token

calculator.cpp:68: syntax error before `<<' token

calculator.cpp:69: syntax error before `<<' token

calculator.cpp:70: syntax error before `>>' token

calculator.cpp:71: syntax error before `<<' token

calculator.cpp:72: syntax error before `>>' token

calculator.cpp:77: syntax error before `<<' token

calculator.cpp:83: syntax error before `<<' token

calculator.cpp:84: syntax error before `<<' token

calculator.cpp:85: syntax error before `>>' token

calculator.cpp:86: syntax error before `<<' token

calculator.cpp:87: syntax error before `>>' token

calculator.cpp:92: syntax error before `<<' token

calculator.cpp:98: syntax error before `<<' token

calculator.cpp:99: syntax error before `<<' token

calculator.cpp:100: syntax error before `>>' token

calculator.cpp:101: syntax error before `<<' token

calculator.cpp:102: syntax error before `>>' token

calculator.cpp:107: syntax error before `<<' token

calculator.cpp:122: syntax error before `<<' token



Compilation exited abnormally with code 1 at Mon Sep 15 23:09:19

 

Help would be much appreciated

 

Thanks in advance.

[Glitz]

For starters, main() should come before the {. Fix that and compile again. That may get rid of most of your errors.

 

Glitz.

[johnnyv]

Okay

 

firstly your structure definition needs to end with a semicolon };

 

you must create an instance of your structure before you can use it "answer answer;"(created an instance of the answer structure named answer, it could be done when you make the structure).

 

you had { before main() not after as was mentioned

you needed to declare what type main() is eg "int main()" so g++ will know what main will return

you could use void main() but thats not recommended.

 

enclose your else if statment code in brackets if there is a fair bit of it.

 

that was about it, here is a version that compiles

 

#include <iostream.h>



struct answer{

 int multiply;

 int add;

 int divide;

 int subtract;

};





int main()

{



int Choice;

int mulnumone;

int mulnumtwo;

int addnumone;

int addnumtwo;

int divnumone;

int divnumtwo;

int subnumone;

int subnumtwo;



answer answer;



while (1) {



 // Menu Heading



 cout << "ttt//////////////////////////n";

 cout << "ttt/////// CALCULATOR ///////n";

 cout << "ttt//////////////////////////n";



 //Menu Choices



 cout << "nttt1) Multiply Numbers n";

 cout << "ttt2) Add Numbers n";

 cout << "ttt3) Divide Numbers n";

 cout << "ttt4) Subtract Numbers n";

 cout << "ttt5) Exit the calculator n";

 cout << "ntttPlease Enter your choice:  ";



 // Find users choice



 cin >> Choice;



 // Accordng to choice Calculate users input



 // Multiplication



if (Choice == 1)

{

 cout << "ntttYou chose to Multiply Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Multiply, after you type each nimber, press enternttt";

 cout << "ntttEnter First Number:  nttt";

 cin >> mulnumone;

 cout << "ntttEnter Second Number:  nttt";

 cin >> mulnumtwo;



 // Calculate the Multiplication Equation



 answer.multiply = mulnumone * mulnumtwo;

 cout << mulnumone << " times " << mulnumtwo << " equals " << answer.multiply << "n";

}



 // Addition



else if (Choice == 2)

{

 cout << "ntttYou chose to Add Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Add, after you type each nimber, press enternttt";

 cout << "ntttEnter First Number:  nttt";

 cin >> addnumone;

 cout << "ntttEnter Second Number:  nttt";

 cin >> addnumtwo;



 // Calculate the Addition Equation



 answer.add = mulnumone + mulnumtwo;

 cout << addnumone << " plus " << addnumtwo << " equals " << answer.add << "n";

}



 // Division



else if (Choice == 3)

{

cout << "ntttYou chose to Divide Numbers.nttt";

cout << "ntttEnter the numbers that you want to Divide, after you type each nimber, press enternttt";

cout << "ntttEnter First Number:  nttt";

cin >> divnumone;

cout << "ntttEnter Second Number:  nttt";

cin >> divnumtwo;





// Calculate the Division Equation



answer.divide = divnumone / divnumtwo;

cout << divnumone << " divided by " << divnumtwo << " equals " << answer.add << "n";

}



// Subtraction



else if (Choice == 4)

{

cout << "ntttYou chose to Subtract Numbers.nttt";

cout << "ntttEnter the numbers that you want to Subtract, after you type each nimber, press enternttt";

cout << "ntttEnter First Number:  nttt";

cin >> subnumone;

cout << "ntttEnter Second Number:  nttt";

cin >> subnumtwo;



//Calculate the Subtraction Equation



answer.subtract = subnumone / subnumtwo;

cout << subnumone << " minus " << subnumtwo << " equals " << answer.subtract << "n";

}



// If users choice was to exit the calculator, exit



else if (Choice == 5)

  {

    cout << "ntttYou chose to Exit the Calculator. Bye.nttt";

    break;

  }



// If users Choice is not valid, must enter again



else

  {

    cout << "ntttYour choice is NOT valid!n";

    cout << "tttPlease enter a CORRECT choice!nnttt";

  }

}



return 0;

}

[Tuxiscool]

Thank you all for your help, it's much appreciated

 

Anyway, about this line

 

answer answer;

 

Can someone please explain in more depth what this does? because i don't really understand it, thanks.

 

And also, im going to try and add a few new features, like Squaring etc. Would it be done like this? (apart from adding it as one of my choices and declaring variables)

 

 else if (Choice == umm whatever)



  {

cout << "ntttYou chose to Square a Number.nttt";

cout << "ntttEnter the numbers that you want to Square, after you type the number, press enternttt";

cout << "ntttEnter Number:  ttt";

cin >> squarenum;



answer.square = squarenum ^2;

cout << "nttt"  << squarenum << " squared " << " equals " << answer.square << "n";

  }

 

That's just a guess but is that how you do squaring in c++? if not, could someone please tell me how? thanks.

[Cannonfodder]

You always have ...

 

x2 = x * x

[johnnyv]

In regards to "answer answer;"

 

you are declaring an instance of the structure answer and calling it answer.

 

it's like int X;

you could have called it answer bob; then you would call bob.multiply , bob.add etc....

 

The structure definition below is just that, it's a definition, the stuct name(in this case answer) becomes a sort of new variable type.

struct answer{

 int multiply;

 int add;

 int divide;

 int subtract;

};

To make use of this new variable type you need to create in instance of it, hence "answer answer;" .

 

You can actually define instances of a stucture when you define the structure as follows

struct answer{

 int multiply;

 int add;

 int divide;

 int subtract;

} answer, bob;

Here two instances of the struct answer have been defined, answer and bob which can be used later in the program.

 

I hope that explains it a bit better. You could look at this page for some more examples.

http://www.cplusplus.com/doc/tutorial/tut3-5.html

 

Oh and another thing, there is an error in your code in the addition part "answer.add = mulnumone + mulnumtwo;" should be addnumone + addnumtwo;.

 

Once you understand this then you should improve you program by adding protections like not allowing a divide by zero error to occur, and preventing users from entering other than ints, eg currently adding a number and letter together gives a rather bad result.

[johnnyv]

Oh for square root in c++ you need to include the math header file #include <math.h>

 

y = sqrt(x);

ref:

http://www.cplusplus.com/ref/cmath/sqrt.html

[ramfree17]

and dont forget to explicitly link the math libraries during compile time. i think its -lm but it might be -lmath.

 

i remember this issue from a newbie post in the local mailing list.

 

ciao!

[Tuxiscool]

Yeah, thanks for that, i had done that already though over a week ago, now it does a few more things aswell.

 

Now im trying to figure out how i can find the size of an angle when i have the value CosA (where A is the angle) and also tanA and sinA.

 

Here's my code so far

 

#include <iostream.h>

#include <math.h>



struct answer{

 double multiply, add, divide, subtract, square, sqrt, tanA, cosine, sine, circumference, semiCircumference;

};



int main()



{

int Choice, choiceCircumference;

 double mulnumone, mulnumtwo, addnumone, addnumtwo, divnumone, divnumtwo, subnumone, subnumtwo, squarenum, sqrtnum, tannumopposite, tannumadjacent, cosnumadjacent, cosnumhypotenuse, sinnumopposite, sinnumhypotenuse, circleDiameter, semiCircleDiameter;



answer answer;



while (1) {



 // Menu Heading



 cout << "ttt##########################n";

 cout << "ttt####### CALCULATOR #######n";

 cout << "ttt##########################n";



 //Menu Choices



 cout << "nttt1) Multiply Numbers n";

 cout << "ttt2) Add Numbers n";

 cout << "ttt3) Divide Numbers n";

 cout << "ttt4) Subtract Numbers n";

 cout << "ttt5) Square Numbers n";

 cout << "ttt6) Find Square Root of number n";

 cout << "ttt7) Find cosA n";

 cout << "ttt8) Find sinA n";

 cout << "ttt9) Find tanA n";

 cout << "ttt10) Find Circumference n";

 cout << "ttt11) Exit the calculator n";

 cout << "ntttPlease Enter your choice:  ";



 // Find users choice



 cin >> Choice;



 // Accordng to choice Calculate users input



 // Multiplication



if (Choice == 1)



  {

 cout << "ntttYou chose to Multiply Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Multiply, after you type each number, press enternttt";

 cout << "ntttEnter First Number:  ttt";

 cin >> mulnumone;

 cout << "ntttEnter Second Number:  ttt";

 cin >> mulnumtwo;



 // Calculate the Multiplication Equation



 answer.multiply = mulnumone * mulnumtwo;

 cout << "nttt"  << mulnumone << " times " << mulnumtwo << " equals " << answer.multiply << "nn";

  }



// Addition



else if (Choice == 2)

  {

 cout << "ntttYou chose to Add Numbers.nttt";

 cout << "ntttEnter the numbers that you want to Add, after you type each number, press enternttt";

 cout << "ntttEnter First Number:  ttt";

 cin >> addnumone;

 cout << "ntttEnter Second Number:  ttt";

 cin >> addnumtwo;



 // Calculate the Addition Equation



 answer.add = addnumone + addnumtwo;

 cout << "nttt" << addnumone << " plus " << addnumtwo << " equals " << answer.add << "nn";

  }



// Division



else if (Choice == 3)



  {

cout << "ntttYou chose to Divide Numbers.nttt";

cout << "ntttEnter the numbers that you want to Divide, after you type each number, press enternttt";

cout << "ntttEnter First Number:  ttt";

cin >> divnumone;

cout << "ntttEnter Second Number:  ttt";

cin >> divnumtwo;



// If divnumtwo equals 0, don't try to divide



if (divnumtwo == 0)



  {

    cout << "ntttSorry, you can not divide by Zero, Please try something else.nn";

  }



// Calculate the Division Equation



else

 {

answer.divide = divnumone / divnumtwo;

cout << "nttt" << divnumone << " divided by " << divnumtwo << " equals " << answer.divide << "nn";

 }

  }



// Subtraction



else if (Choice == 4)



  {

cout << "ntttYou chose to Subtract Numbers.nttt";

cout << "ntttEnter the numbers that you want to Subtract, after you type each number, press enternttt";

cout << "ntttEnter First Number:  ttt";

cin >> subnumone;

cout << "ntttEnter Second Number:  ttt";

cin >> subnumtwo;



//Calculate the Subtraction Equation



answer.subtract = subnumone - subnumtwo;

cout << "nttt"  << subnumone << " minus " << subnumtwo << " equals " << answer.subtract << "nn";

  }



// Squaring



else if (Choice == 5)



  {

    cout << "ntttYou chose to Square a Number.nttt";

    cout << "ntttEnter the number you want to Square:  ttt";

    cin >> squarenum;



    // Calculate the Squaring Equation



    answer.square = squarenum * squarenum;

    cout << "nttt" << squarenum << " squared equals " << answer.square << "nn";

  }



// Square Rooting



else if (Choice == 6)



  {

    cout << "ntttYou chose to find the Square Root of a number.nttt";

    cout << "ntttEnter the number you want the Square Root of:  ttt";

    cin >> sqrtnum;



    //Calculate Squaring Equation



    answer.sqrt = sqrt (sqrtnum);

    cout << "nttt" << "The square root of " << sqrtnum << " is " << answer.sqrt << "nn";

  }



// Finding cosA



else if (Choice == 7)



  {

    cout << "ntttYou chose to find cosA.nttt";

    cout << "ntttEnter the size of the adjacent side:  ttt";

    cin >> cosnumadjacent;

    cout << "ntttEnter the size of the hypotenuse:  ttt";

    cin >> cosnumhypotenuse;



    // Find cosA



    answer.cosine = cosnumadjacent / cosnumhypotenuse;

    cout << "nttt" << "cosA equals " << answer.cosine << "nn";

  }



// Finding sinA



else if (Choice == 8)



  {

    cout << "ntttYou chose to find sinA.nttt";

    cout << "ntttEnter the size of the opposite side: ttt";

    cin >> sinnumopposite;

    cout << "ntttEnter the size of the hypotenuse:  ttt";

    cin >> sinnumhypotenuse;



    // Find sinA



    answer.sine = sinnumopposite / sinnumhypotenuse;

    cout << "nttt" << "sinA equals " <<  answer.sine << "nn";

  }



// Finding tanA



else if (Choice == 9)



  {

    cout << "ntttYou chose to find tanA.nttt";

    cout << "ntttEnter the size of the opposite side:  ttt";

    cin >> tannumopposite;

    cout << "ntttEnter the size of the adjacent side:  ttt";

    cin >> tannumadjacent;



    // Find tanA



    answer.tanA = tannumopposite / tannumadjacent;

    cout << "nttt" << "tanA equals " << answer.tanA << "nn";

  }



// Finding Circumference



else if (Choice == 10)

{

    cout << "ntttWhat do you want to find the circumference of? n";

    cout << "nttt1) Circle. n";

    cout << "ttt2) Semicircle. n";

    cout << "tttWhat is your choice?  ";

    cin >> choiceCircumference;



if (choiceCircumference == 1)



  {

    cout << "ntttYou chose to find the circumfefence of a circle.nttt";

    cout << "ntttEnter the diameter of the circle:  ttt";

    cin >> circleDiameter;



    // Find Circumference of circle



    answer.circumference = circleDiameter * 3.14159;

    cout << "nttt" << "The circumference of the circle with the diameter " << circleDiameter << " is " << answer.circumference << "n";

  }



  else if (choiceCircumference == 2)



  {

  cout << "ntttYou chose to find the circumference of a Semicircle.nttt";

  cout << "ntttEnter the diameter of the Semicircle:  ttt";

  cin >> semiCircleDiameter;



  // Find Circumferene of semicircle



  answer.semiCircumference = (semiCircleDiameter * 3.14159) * 0.5;

  cout << "nttt" << "The circumference of the semicircle with the diameter " << semiCircleDiameter << " is " << answer.semiCircumference << "n";

  }

  }



 // If users choice was to exit the calculator, exit



else if (Choice == 11)

  {

    cout << "ntttYou chose to Exit the Calculator. Bye.nttt";

    break;

  }



// If users Choice is not valid, must enter again



else

  {

    cout << "ntttYour choice is NOT valid!n";

    cout << "tttPlease enter a CORRECT choice!nn";

  }

}



return 0;

}

[/code]

[Glitz]

try these functions:

 

ACOS()

ASIN()

ATAN()

 

The return values are in radians.

 

Glitz.

[Dr Thrall]

btw why don't u use-switch case in place of if-else

so far i know, switch-case use for known selection, & if for comparison, an unknown condition ( like if user hit the key or what ... ) .

using switch-case, ur code become more attractive & clean ...

& use getchar in place on cin, for getting choice from user. as if user keep pressing enter key, cin still waits for input & ur display screen may disappear ( untill u use method of istream not to do this ) & u can't c the choice menu untill u press wrong key, or return from ur calculation

[Tuxiscool]

Thank you very much for all of your help and Dr Thrall, i will try out your advice when i can be bothered ;), but for a start, trying ACOS() , ASIN(), and ATAN() produces the following errors.

 

calculator.cpp: In function `int main()':

calculator.cpp:177: `ACOS' undeclared (first use this function)

calculator.cpp:177: (Each undeclared identifier is reported only once for each function it appears in.)

calculator.cpp:197: `ASIN' undeclared (first use this function)

calculator.cpp:217: `ATAN' undeclared (first use this function)

 

do i need to add an extra header file or is it something different i do?

 

Thanks in Advance

[Cannonfodder]

When something is generating an undefined error then the compilier can't find a reference to it. If it can't find a reference to it then it can't find the code for it. You need to make sure the 3 functions or the header file for the functions are declared. One good way to go about figuring this out is to do a google search on it..

 

E.g.

 

acos c++

 

and look for how to reference them.

 

Of course you can always read your manual too :)

[Glitz]

Oops! I didn't mean for them to be in uppercase. Try

 

asin()

acos()

atan()

 

Sorry for the confusion.

 

Glitz.