first foray into classes; need a bit of help

[jay5965]

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

#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

#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

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.

[Philip Nicoletti]

void String::String()
{

Same thing for the other functions in class String

[Lindley]

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?

[Richard.J]

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

void string();

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

[D_Drmmr]

mystring.h

#include <iostream>
using namespace std;

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.

[standard]

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