Question

I had written C++ code for a problem. After that i have tried to write a C code that can solve the same problem.
The header file Bit.h is:

#ifndef Bit_included
#define Bit_included

struct Bit
{
    int width;
    int value;
};
void init();
void initvalues(int v, int w);
void initcopy(const Bit& b);
int getWidth();
int getValue();
Bit & plus(int newval);
#endif //Bit_included

The file Bit.c is:

#include "Bit.h"
#include "math.h"
using namespace std;
void init()
{
    value=0;
    width=0;
}
void initvalues(int v,int w)
{
    value=v;
    width=w;
}
void initcopy(const Bit& b)
{
    value=b.value;
    width=b.width;
}
int getWidth()
{
    return width;
}
int getValue()
{
    return value;
}
Bit & plus(int newval)
{
    value+=newval;
    if(value>=pow(2,width))
     cout<<"Overflow";
    return *this;
}

Error in the header files are:

Line 11: error: expected ';', ',' or ')' before '&' token
Line 14: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&' token

Error in Bit.c are:

Line 3: error: expected '=', ',', ';', 'asm' or '__attribute__' before 'namespace'
In function 'init':
Line 6: error: 'value' undeclared (first use in this function)
Line 6: error: (Each undeclared identifier is reported only once
Line 6: error: for each function it appears in.)
Line 7: error: 'width' undeclared (first use in this function)
In function 'initvalues':
Line 11: error: 'value' undeclared (first use in this function)
Line 12: error: 'width' undeclared (first use in this function)
t.c: At top level:
Line 14: error: expected ';', ',' or ')' before '&' token
In function 'getWidth':
Line 21: error: 'width' undeclared (first use in this function)
In function 'getValue':
Line 25: error: 'value' undeclared (first use in this function)
t.c: At top level:
Line 27: error: expected '=', ',', ';', 'asm' or '__attribute__' before '&' token

How can i write the correct code?

Answer 1

C and C++ are two rather different languages. Your code is neither valid C nor valid C++. It is, however, using quite a few constructs and features that are specific to C++ and are not available in C.

If you wish to learn C, my advice would be to pick up a good textbook. It’ll be much more efficient than just guessing your way.

Here is a good starting point: The Definitive C Book Guide and List