Question

can someone point out the mistake in my c++ program. i keep getting error c2240 "cannot convert from void to double"

Answer 1

#include <iostream>
using namespace std;

void consoleUI(); //prototype header

void main()
{
consoleUI(); //call function
}

//prototypes

void calcPaint(int, int, double&);
void calcHours(int, double, double&);
void calcPcost(double, double, double&);
void calcLabor(double, double, double&);
void calcTotal(double, double, double&);

void consoleUI()
{
int r, sqft;
double paint;

do
{
cout<<"Enter Number of Rooms: ";
cin>>r;
}
while (r<1);
do
{
cout<<"Enter Price of Paint Per Gallon: $";
cin>>paint;
}
while (paint<10.00);
do
{
cout<<"Enter Square Feet: ";
cin>>sqft;
}
while (sqft<0);

int ft=115, l=8;
double labor=18.00, p=0.00, h=0.00, pc=0.00, L=0.00, t=0.00;
double gal, hours, pcost, costLabor, total;

gal= calcPaint(sqft, ft, p);
hours= calcHours(l, gal, h);
pcost= calcPcost(gal, paint, pc);
costLabor= calcLabor(hours, labor, L);
total= calcTotal(pcost, costLabor, t);

cout<<"Gallons of Paint Required: "<<gal<<endl
<<"Hours of Labor: "<<hours<<endl
<<"Paint Cost: "<<pcost<<endl
<<"Labor Charge: "<<costLabor<<endl
<<"Total Cost of Paint Job: "<<total<<endl;
}

void calcPaint(int sqft, int ft, double& p)
{
p= sqft/ft;
}

void calcHours(int l, double gal, double& h)
{
h= l*gal;
}

void calcPcost(double gal, double paint, double& pc)
{
pc=gal*paint;
}

void calcLabor(double hours, double labor, double& L)
{
L=hours*labor;
}

void calcTotal(double pcost, double costLabor, double& t)
{
t=pcost+costLabor;
}

Answer 2

I believe that the prototypes should be before main().

FWIW, I don't understand the conditions in the while statements.

Answer 3

ohhh let me see. and its input validation cause paint price cant be more than ten dollars and square feet cant be negative, as per the assignment.

Answer 4

still build error with the prototypes before main.

Answer 5

hulppp.

Answer 6

sqft is evaluated in a while statement without having a value assigned to it in consoleUI.

gal= calcPaint(sqft, ft, p);
hours= calcHours(l, gal, h);
pcost= calcPcost(gal, paint, pc);
costLabor= calcLabor(hours, labor, L);
total= calcTotal(pcost, costLabor, t);

are all called assigning the return value of void functions. They're probably the culprits.

Answer 7

ahh so true. now to figure out how to fix it.

Answer 8

the calcX functions are all defined as void. they all expect to set the result in a reference variable passed into them.

Answer 9

the last parameter of each of the calcX methods receive the result of the calculation.

Answer 10

i dont understand how to fix it!

Answer 11

so, for example, instead of:
gal= calcPaint(sqft, ft, p);
you need to do:
calcPaint(sqft, ft, gal);

Answer 12

ah okayy. and then just make p the cout?

Answer 13

another way would be to change all the calX methods so that they return the result instead. e.g.:
void calcPaint(int sqft, int ft, double& p)
{
p= sqft/ft;
}
would become:
double calcPaint(int sqft, int ft)
{
return sqft/ft;
}

Answer 14

this would then be used as:
gal= calcPaint(sqft, ft);

Answer 15

#include <iostream>
using namespace std;

void calcPaint(int, int, double&);
void calcHours(int, double, double&);
void calcPcost(double, double, double&);
void calcLabor(double, double, double&);
void calcTotal(double, double, double&);

void consoleUI()
{
int r, sqft;
double paint;


cout<<"Enter Number of Rooms: ";
cin>>r;

cout<<"Enter Price of Paint Per Gallon: $";
cin>>paint;

cout<<"Enter Square Feet: ";
cin>>sqft;

if (r>11 && paint>10.00 && sqft>0)
{

int ft=115, l=8;
double labor=18.00, p=0.00, h=0.00, pc=0.00, L=0.00, t=0.00;

calcPaint(sqft, ft, p);
calcHours(l, p, h);
calcPcost(p, paint, pc);
calcLabor(h, labor, L);
calcTotal(pc, L, t);

cout<<"Gallons of Paint Required: "<<p<<endl
<<"Hours of Labor: "<<h<<endl
<<"Paint Cost: "<<pc<endl
<<"Labor Charge: "<<L<<endl
<<"Total Cost of Paint Job: "<<t<<endl;
}
else
{
cout<<"Error!"<<endl;
}
}

void calcPaint(int sqft, int ft, double& p)
{
p= sqft/ft;
}

void calcHours(int l, double p, double& h)
{
h= l*p;
}

void calcPcost(double p, double paint, double& pc)
{
pc=p*paint;
}

void calcLabor(double h, double labor, double& L)
{
L=h*labor;
}

void calcTotal(double pc, double &L, double& t)
{
t=pc+L;
}

Answer 16

now its saying there is a mismatch in formal parameter list at
<<"Labor Charge: "<<L<<endl

Answer 17

neverminds got itttt.