What is missing in this c++ program? printing calculations - c++

Question

#include <iostream>
#include <iomanip>
using namespace std;
int main () // print to console: 3.0*5.0=15.00
{
double a;
double b;
a =(3.0);
b =(5.0);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << "* " << b << "\n" << endl;
cout << "------" << endl;
cout << fixed << setprecision (2) << a*b << "\n" << endl;
return 0;
}
int calculate (int a, int b, int c) // print to console: (7.1*8.3)-2.2=56.73
{
double a;
double b;
double c;
a = (7.1);
b = (8.3);
c = (2.2);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << "* " << b << "\n" << endl;
cout << "- " << c << "\n" << endl;
cout << "------" << endl;
cout << setprecision(2) << (a*b)-c << "\n" << endl;
}
int calculation (int a, int b, int c) // print to console: 3.2/(6.1*5.0)=0.10
{
double a;
double b;
double c;
a=(3.2);
b=(6.1);
c=(5.0);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << " /(6.1*5.0)" << endl; //how can I use variables instead of using quotes?
cout << "------" << endl;
cout << setprecision(2) << a/(b*c) << "\n" << endl;
system("PAUSE");
return 0;
}
I have used a repetitive layout that I was hoping would print 3 functions vertically so that decimals all line up. I cannot seem it to get to print without errors and think I don't understand the error outputs enough to make necessary changes. I don't know if I am redefining the variables properly or if I am putting them together properly (using {}).
Thanks to anyone who can help me get this to work.
Here is the output:
(7): error C2082: redefinition of formal parameter 'a'
(8): error C2082: redefinition of formal parameter 'b'
(9): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
(10): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
(21): error C2082: redefinition of formal parameter 'a'
(22): error C2082: redefinition of formal parameter 'b'
(23): error C2082: redefinition of formal parameter 'c'
(24): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
(25): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
(26): warning C4244: '=' : conversion from 'double' to 'int', possible loss of data
(34): error C2601: 'calculation' : local function definitions are illegal
(20): this line contains a '{' which has not yet been matched
(51): fatal error C1075: end of file found before the left brace '{'
How would I fix these errors?

Answer 1

You missed the closing brace after:
int calculate (int a, int b, int c) // print to console: (7.1*8.3)-2.2=56.73
{
....
....
cout << setprecision(2) << (a*b)-c << "\n" << endl;
}
^^^^
Since you have same named symbols in both functions the missing brace leads to the symbol names being used more than once violating the One Definition Rule and hence the redefinition error.
Also, note what #Ed.S rightly points out in comments.
Also, note the warning of type conversion you may want to consider that in your program logic.

Answer 2

First of all:
int main(int, int) - very non-standard program entry point
Next one :
int main (int a, int b) // print to console: 3.0*5.0=15.00
{
double a;
double b;
You are redefining formal parameters a and b
That's it, this is what your compiler is saying:
(7): error C2082: redefinition of formal parameter 'a'
(8): error C2082: redefinition of formal parameter 'b'
.
int calculate (int a, int b, int c) // print to console: (7.1*8.3)-2.2=56.73
{
double a;
double b;
double c;
You have same local variables and formal parameter names, I don't think this is what you are expecting.
And last one:
You are missing closing bracket "}" at the end of calculate function.
#include <iostream>
#include <iomanip>
using namespace std;
int main () // print to console: 3.0*5.0=15.00
{
double a;
double b;
a =(3.0);
b =(5.0);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << "* " << b << "\n" << endl;
cout << "------" << endl;
cout << fixed << setprecision (2) << a*b << "\n" << endl;
return 0;
}
int calculate () // print to console: (7.1*8.3)-2.2=56.73
{
double a;
double b;
double c;
a = (7.1);
b = (8.3);
c = (2.2);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << "* " << b << "\n" << endl;
cout << "- " << c << "\n" << endl;
cout << "------" << endl;
cout << setprecision(2) << (a*b)-c << "\n" << endl;
}
int calculation () // print to console: 3.2/(6.1*5.0)=0.10
{
double a;
double b;
double c;
a=(3.2);
b=(6.1);
c=(5.0);
cout << " " << fixed << setprecision (1) << a << "\n" << endl;
cout << b << "*" << c << endl; //how can I use variables instead of using quotes?
cout << "------" << endl;
cout << setprecision(2) << a/(b*c) << "\n" << endl;
system("PAUSE");
return 0;
}

Answer 3

You're missing the } after your int calculate function. Although unrelated, you also don't have to call fixed and setprecision multiple times.