John A
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User-Defined Function - part 2
Hey everyone, this is a big one.
The question has asked that I define functions and then write the function main to test the functions I wrote. I keep getting the following error at my first cout in main:
error C2679: binary '<<' : no operator found which takes a right-hand operand of type 'void' (or there is no acceptable conversion)
I'm not sure what this is saying.
In addition, I need help with defining two of my functions and writing code to test them. They are as follows:
1. Write the definition of the function nextChar that sets the value of z to the next character stored in z.
2. Write the definition of the function funcOne that prompts the user to input a number. The function then changes the value of x to 2 times the old value of x plus the value of y minus the value entered by the user.
Now, with #2 I'm pretty sure I have the function defined right, though I don't know how to test it. #1 though, I have no clue how to define that function, though I did attempt it =/.
Could someone look through my code, and let me know if they notice any huge mistakes? This is our second chapter on user-defined functions, so I'm still learning about call by reference and whatnot. I have commented my code minimaly to assist you in finding the parts I'm having a tough time with.
Thanks guys! :mrgreen:
code:
<pre><code>#include <iostream>
#include <iomanip>
using namespace std ;
void initialize ( int& , int& , char& ) ;
void getHoursRate ( double& , double& ) ;
double payCheck ( double& , double& ) ;
void printCheck ( double , double, double ) ;
int main()
{
int x ;
int y ;
int w ;
char z ;
double rate ;
double hours ;
double amount ;
cout << initialize( x , y , z ) << endl ; //error is here
cout << getHoursRate() << endl ;
cout << payCheck( hours , rate ) << endl ;
printCheck( hours, rate, amount ) << endl ;
cout << funcOne( w, x, y ) ; //confusion starts here
cout <<
}
void initialize ( int& x, int& y, char& z )
{
x = y = 0 ;
z = ' ' ;
}
void getHoursRate ( double& hours , double& rate )
{
cout << "Hours worked: " << endl ;
cin >> hours ;
cout << "Rate: " << endl ;
cin >> rate ;
}
double payCheck ( double& hours, double& rate )
{
double pay ;
int ot ;
if ( (hours - 40 <= 0 ) )
pay = rate * hours ;
else
{
ot = hours - 40 ;
pay = (40 * rate) + (ot * rate * 1.5) ;
}
return pay ;
}
void printCheck ( double hours , double rate , double pay )
{
cout << setprecision(2) << fixed << showpoint << setfill('.') << left ;
cout << "Hours" << setw(15) << "Rate" << setw(15) << "Amount Due" << endl << endl ;
cout << hours << setw(15) << "$" << rate << setw(15) << "$" << pay << endl ;
}
void funcOne ( double in, int x, int y ) //number 2 in my post
{
cout << "Input a value: " << endl ;
cin >> in ;
x = x * x + ( y - in ) ;
}
char nextChar ( char ch ) //number 1 in my post
{
ch = ch++ ;
}</code></pre>2. Write the definition of the function funcOne that prompts the user to input a number. The function then changes the value of x to 2 times the old value of x plus the value of y minus the value entered by the user. Now, with #2 I'm pretty sure I have the function defined right, though I don't know how to test it. code:
<pre><code>void funcOne ( double in, int x, int y ) //number 2 in my post { cout << "Input a value: " << endl ; cin >> in ; x = x * x + ( y - in ) ; // <----Wrong }</code></pre>
With this function you are squaring x instead of doubling it (ie use 2*x instead of x*x). To test it, simply do some simple math in your head, using different values of x and y....then implement that in your code...if your code gives you different answers, then, unless you did the math wrong yourself, you know there is a problem with your code...
As for part 1, I believe the instructions are referring to c-strings...how much do you know about c-strings?
Ok, I've modified my code, and am getting an error that says:
error C2563: mismatch in formal parameter list
This is at the same line with the comment //error is here
I've called the void functions outside of a cout, and have put cout statements inside of the function to test them. What am I doing wrong? =/
<pre><code>#include <iostream>
#include <iomanip>
using namespace std ;
void initialize ( int& , int& , char& ) ;
void getHoursRate ( double& , double& ) ;
double payCheck ( double& , double& ) ;
void printCheck ( double , double, double ) ;
void funcOne ( doulbe, int, int ) ;
void nextChar ( char ) ;
int main()
{
int x ;
int y ;
int w ;
char z ;
double rate ;
double hours ;
double amount ;
initialize( x , y , z ) << endl ; //error is here
getHoursRate() << endl ;
cout << payCheck( hours , rate ) << endl ;
printCheck( hours, rate, amount ) << endl ;
funcOne( w, x, y ) ; //confusion starts here
nextChar ( z ) ;
}
void initialize ( int& x, int& y, char& z )
{
x = y = 0 ;
z = ' ' ;
cout << "Inside initialize-function: " << endl ;
cout << "The values of 'x', 'y' and 'z', respectively are: " x << "\t" << y << "\t" << z << endl << endl ;
}
void getHoursRate ( double& hours , double& rate )
{
cout << "Hours worked: " << endl ;
cin >> hours ;
cout << "Rate: " << endl ;
cin >> rate ;
cout << "Inside getHoursRate-function: " << endl ;
cout << "The values of 'hours' and 'rate', respectively are: " << hours << "\t" << rate << endl << endl ;
}
double payCheck ( double& hours, double& rate )
{
double pay ;
int ot ;
if ( (hours - 40 <= 0 ) )
pay = rate * hours ;
else
{
ot = hours - 40 ;
pay = (40 * rate) + (ot * rate * 1.5) ;
}
return pay ;
}
void printCheck ( double hours , double rate , double pay )
{
cout << setprecision(2) << fixed << showpoint << setfill('.') << left ;
cout << "Hours" << setw(15) << "Rate" << setw(15) << "Amount Due" << endl << endl ;
cout << hours << setw(15) << "$" << rate << setw(15) << "$" << pay << endl ;
}
void funcOne ( double in, int x, int y ) //number 2 in my post
{
cout << "Input a value: " << endl ;
cin >> in ;
x = x * 2 + ( y - in ) ;
cout << "Inside funcOne-function: " << endl ;
cout << "The value of 'x' is: " << x << endl << endl ;
}
char nextChar ( char ch ) //number 1 in my post
{
cout << "Inside nextChar-function: " << endl ;
cout << "Initial character stored in 'ch' is: " << ch << endl ;
ch = ch++ ;
cout << "The character stored in 'ch' after incriment is: " << ch << endl << endl ;
}</code></pre> initialize( x , y , z ) << endl ;
You can't do this in C++ esp when initialize doesn't return anything and even if it did, you aren't specifying the stream to which the output should be redirected.
~s.o.s~
Failure as a human
Administrator
11,938 posts since Jun 2006
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As for part 1, I believe the instructions are referring to c-strings...how much do you know about c-strings?
i don't =/
As for part 1, I believe the instructions are referring to c-strings...how much do you know about c-strings?
I don't think so. Although, I don't know what the instructions mean, either.
Can you give us an example of the operation?
WaltP
Posting Sage w/ dash of thyme
Moderator
10,506 posts since May 2006
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Just an update, thanks to everyone who helped. Here's the finalized code. This one is solved :D
<pre><code>/*****************************************************
* COSC 230 - Structured Programming
* Chapter 7: Programming Exercise 1
* Apr. 4, 2007
*
* Discription:
* blah
******************************************************/
//header files
#include <iostream>
#include <iomanip>
using namespace std ;
//function prototypes
void initialize ( int& , int& , char& ) ;
void getHoursRate ( double& , double& ) ;
double payCheck ( double& , double& ) ;
void printCheck ( double , double, double ) ;
void funcOne ( double, int, int ) ;
void nextChar ( char ) ;
int main()
{
int x ;
int y ;
int w ;
char z ;
double rate ;
double hours ;
double amount ;
initialize( x , y , z ) ; //test initialize-func.
getHoursRate(hours, rate) ; //test initialize-func.
amount = payCheck( hours, rate ) ; //initialize amount to paycheck-func.
cout << "*** Inside payCheck-function ***" << endl << payCheck( hours , rate ) << endl ; //test payCheck-func.
printCheck( hours, rate, amount ) ; //test printCheck-func.
funcOne( w, x, y ) ; //test funcOne-func.
nextChar ( z ) ; //test nextChar-func.
}
void initialize ( int& x, int& y, char& z )
{
x = y = 0 ;
z = ' ' ;
cout << "*** Inside initialize-function ***" << endl ;
cout << "The values of 'x' and 'y', respectively are: " << x << " and " << y << endl ;
cout << "The character stored in z is: " << z << "(space character)" << endl << endl ;
}//end void initialize
void getHoursRate ( double& hours , double& rate )
{
cout << "Hours worked: " << flush ;
cin >> hours ;
cout << "Rate: " << flush ;
cin >> rate ;
cout << endl << "*** Inside getHoursRate-function ***" << endl << endl ;
cout << "The values of 'hours' and 'rate', respectively are: " << hours << "\t" << rate << endl << endl ;
}//end getHoursRate
double payCheck ( double& hours, double& rate )
{
double pay ;
int ot ;
if ( (hours - 40 <= 0 ) )
pay = rate * hours ;
else
{
ot = hours - 40 ;
pay = (40 * rate) + (ot * rate * 1.5) ;
}
return pay ;
}//end double payCheck
void printCheck ( double hours , double rate , double amount )
{
cout << "*** Inside printCheck-function ***" << endl ;
cout << setprecision(2) << fixed << showpoint << setfill('.') ;
cout << "Hours" << setw(20) << right << "Rate" << setw(25) << right << "Amount Due" << endl ;
cout << hours << setw(15) << "$" << rate << setw(15) << "$" << amount << endl << endl ;
}//end void printCheck
void funcOne ( double in, int x, int y )
{
cout << "Input a value: " << flush ;
cin >> in ;
cout << endl ;
x = x * 2 + ( y - in ) ;
cout << "*** Inside funcOne-function ***" << endl ;
cout << "The value of 'x' is: " << x << endl << endl ;
}//end void funcOne
void nextChar ( char ch )
{
cout << "*** Inside nextChar-function ***" << endl ;
cout << "Initial character stored in 'ch' is: " << ch << endl ;
ch = ch++ ;
cout << "The character stored in 'ch' after increment is: " << ch << endl << endl ;
}//end nextChar</code></pre>This question has already been solved
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