first foray into classes; need a bit of help

The assignment is to write our own string function; not a big deal. However I dont think that I am declaring everything correctly as I am getting 20-some nearly identical errors that I cant get to go away. Any insight into the issue here would be greatly appreciated.

mystring.h

Code:

---

#include <iostream>
using namespace std;


class String
{
public:
        void string();
        void assign(const char s[]);
        void append(const String &str);
        int compare_to(const String &str);
        void print() const;
        int length() const;
        char element(int i);

private:
        int lngth;
        char strng[100];
}

---

mystring.cpp

Code:

---

#include "mystring.h"
#include <iostream>
using namespace std;


void String()
{

        for (int i=0;i<100;i++)
        {
                strng[i]='\0';
        }
}
void assign(const char s[])
{
        lngth=0;
        for (int i=0;i<100;i++)
        {
                strng[i]=s[i];
                lngth++;
        }

}
void append(const String &str)
{
        int i,n;
        for (i=0;i<100 && strng[i]!='\0';i++)
        {
        }
        for (n=0; *(str+n)=!'\0'; n++,i++)
        {
                strng[i]=*(str+n);
                lngth++;
        }

}
int compare_to(const String &str)
{
        int i, n, check=0;
        for (i=0;(i<100 && strng[i]!='\0')&&(n<100 && *(str+n)!='\0')&& check=0;i++)
        {
                if (strng[i]<*(str+n))
                        check=-1;
                if (strng[i]>*(str+n))
                        check=1;
        }
        return check;



}
void print() const
{
        for (int i=0; strng[i]!='\0';i++)
                cout<<strng[i];

}
int length() const
{
        return lngth;

}
char element(int i)
{
        if (i<100 && strng[i]=!'\0')
                return strng[i];
        else
                cerr<<"Element out of range";
                return '\0';
}

---

....error messages

Code:

---

1>mystring.cpp
error C2143: syntax error : missing ';' before 'using'
(11) : error C2065: 'strng' : undeclared identifier
(16) : error C2065: 'lngth' : undeclared identifier
(19) : error C2065: 'strng' : undeclared identifier
(20) : error C2065: 'lngth' : undeclared identifier
(24) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
(24) : error C2143: syntax error : missing ',' before '&'
(27) : error C2065: 'strng' : undeclared identifier
(30) : error C2065: 'str' : undeclared identifier
(32) : error C2065: 'strng' : undeclared identifier
(32) : error C2065: 'str' : undeclared identifier
(33) : error C2065: 'lngth' : undeclared identifier
(37) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int
(37) : error C2143: syntax error : missing ',' before '&'
(40) : error C2143: syntax error : missing ';' before 'for'
(40) : error C2065: 'strng' : undeclared identifier
(40) : error C2065: 'str' : undeclared identifier
(42) : error C2065: 'strng' : undeclared identifier
(42) : error C2065: 'str' : undeclared identifier
(44) : error C2065: 'strng' : undeclared identifier
(44) : error C2065: 'str' : undeclared identifier
(53) : error C2270: 'print' : modifiers not allowed on nonmember functions
(54) : error C2065: 'strng' : undeclared identifier
(55) : error C2065: 'strng' : undeclared identifier
(59) : error C2270: 'length' : modifiers not allowed on nonmember functions
(60) : error C2065: 'lngth' : undeclared identifier
(65) : error C2065: 'strng' : undeclared identifier
(66) : error C2065: 'strng' : undeclared identifier

---

the above errors were all attributed to mystring.cpp. The driver file was provided, and I am confident It it error-free.

Code:

---

void String::String()
{

---

Same thing for the other functions in class String

Make sure the constructor name is capitalized in the h file, too.

While I don't know the specific requirements of your assignment, I'll point out that using a fixed-size char array to store the underlying string severely limits the usefulness of a string class. Perhaps a future assignment will be to overcome that limitation?

your header file is missing the semicolon after the definition of your class, that is the first error your compiler complains about.
and if

Code:

---

void string();

---

should be the constructor of your class, use a capital 'S' as Lindley suggested and omit the 'void'.

Quote:

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Originally Posted by jay5965

mystring.h

Code:

---

#include <iostream>
using namespace std;

---

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It's bad style to put a using namespace directive in a header file. This way the directive will be put in every file that includes this header, effectively eliminating the advantages of a namespace.

You don't need to include iostream at any rate.