1001. The String Class

#include <iostream>
#include <string>
#include <cstring>
using namespace Std;
Class String {

Public

String (); str = ""

String (const char*); str = "ABC"

String (const string&); str = other_string

string& operator= (const char *);

string& operator= (const string&);

String operator+ (const string&);

~string ();

char& operator[] (int i);

Char operator[] (int i) const;

int size () const;

string& operator+= (const string&);

string& operator+= (const char*);

Friend ostream& operator<< (ostream&, const string&);

Friend istream& operator>> (istream&, string&);

friend bool operator== (const string& x, const char* s);

friend bool operator== (const string& x, const string& y);

friend bool Operator!= (const string& x, const char* s);

friend bool Operator!= (const string& x, const string& y);

Private

Char *str;

};

String::string () {
str = new CHAR[1];
str[0]= ' + ';
}

String::string (const char* a) {
int t = strlen (a) +1;
str = new Char[t];
str = strcpy (str,a);
str[t-1]= ' + ';
}

String::string (const string& b) {
int T=strlen (B.STR) +1;
str = new Char[t];
str = strcpy (STR,B.STR);
str[t-1]= ' + ';
}

string& string::operator= (const char *b) {
int T=strlen (b) +1;
str = new Char[t];
str = strcpy (STR,B);
str[t-1]= ' + ';
return *this;
}

string& string::operator= (const string& b) {
int T=strlen (B.STR) +1;
str = new Char[t];
Str =strcpy (STR,B.STR);
str[t-1]= ' + ';
return *this;
}

String string::operator+ (const string& b) {

String str1;
str1 = new Char[strlen (B.STR) +1+strlen (THIS->STR)];
for (int i=0;i<strlen (THIS->STR); i++) {
str1.str[i]=this->str[i];
}
for (int j=strlen (THIS->STR); J<strlen (B.STR) +strlen (THIS->STR); j + +) {
Str1.str[j]=b.str[j-strlen (THIS->STR)];
}
Str1[strlen (B.STR) +strlen (this->str)]= ' + ';
return str1;
}

String::~string () {
delete [] str;
}

char& string::operator[] (int i) {
return str[i];
}

Char string::operator[] (int i) const{
return str[i];
}

int string::size () const{
return strlen (str);
}

string& string::operator+= (const string& b) {

int L=strlen (str) +strlen (B.STR);
Char *p=new char[l+10];
strcpy (P,STR);
strcat (P,B.STR);
strcpy (STR,P);
return *this;
}

string& string::operator+= (const char* b) {

int L=strlen (str) +strlen (b);
Char *p=new char[l+1];
strcat (P,STR);
strcat (P,B);
strcpy (STR,P);
return *this;
}

ostream& operator<< (ostream& A, const string& b) {
a<<b.str;
return A;
}

istream& operator>> (istream& A, string& b) {
a>>b.str;
return A;
}

BOOL operator== (const string& x, const char* s) {
if (strlen (X.STR)!=strlen (s)) return false;
for (int i=0;i<strlen (X.STR); i++) {
if (X.str[i]!=s[i]) return false;
}
return true;
}

BOOL operator== (const string& x, const string& s) {
if (strlen (X.STR)!=strlen (S.STR)) return false;
for (int i=0;i<strlen (X.STR); i++) {
if (X.str[i]!=s.str[i]) return false;
}
return true;
}

BOOL Operator!= (const string& x, const char* s) {
if (strlen (X.STR)!=strlen (s)) return true;
int count=0;
for (int i=0;i<strlen (s); i++) {
if (X.str[i]!=s[i]);
count++;
}
if (Count==strlen (s)) return false;
else return true;
}

BOOL Operator!= (const string& x, const string& s) {
if (strlen (X.STR)!=strlen (S.STR)) return true;
int count=0;
for (int i=0;i<strlen (S.STR); i++) {
if (X.str[i]!=s[i]);
count++;
}
if (Count==strlen (S.STR)) return false;
else return true;
}

String F1 (String A, string b)

{

A[2] = ' x ';

char C = b[2];

cout << "in F:" << a << ' << b << ' ' << c << ' \ n ';

return b;

}

void F2 (String s, const string& R)

{

Char C1 = s[1]; C1 = s.operator[] (1). Operator CHAR ()

S[1] = ' C '; S.operator[] (1). operator= (' C ')

char C2 = r[1]; C2 = r.operator[] (1)

R[1] = ' d '; Error:assignment to Non-lvalue Char, r.operator[] (1) = ' d '

}

void F ()

{

String x, y, S;

cout << "Please enter strings\n";

Cin >> x >> y;

cout << "x=" << x << ", y =" << y << ' \ n ';

y = F1 (x, y);

cout << y << Endl;

F2 (x, y);

cout << "s = \" "<< s <<" \ "" << Endl;

s = "abc";

cout << "s = \" "<< s <<" \ "" << Endl;

cout << "\" "<< x <<" \ "+ \" "<< y <<" \ "=" << "\" "<< x+y <<" \ "\ n";

String z = x;

cout<<z<<endl;

if (x! = z) cout << "x corrupted!\n";

X[0] = '! ';

if (x = = z) cout << "Write failed!\n";

cout << "Exit:" << x << ' << z << ' \ n ';

z = s;

if (s! = z) cout << "s corrupted!\n";

S[0] = '! ';

if (s = = z) cout << "Write failed!\n";

cout << "exit:" << s << ' << z << ' \ n ';

}

int main ()

{

int T;

Cin >> T;

while (t--)

{

f ();

}

}

1001. The String Class