C++ ostream output wrong [closed] - c++

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I have a problem and I can't solve it.
note: I can't use any string/strlen/strcmp and such functions
My problem is when I'm trying to print obj after cin, when I don't put him value it prints garbage, and if I put value it change it by cin it print it well.
#ifndef __STRING_H__
#define __STRING_H__
#include <iostream>
using namespace std;
class String {
private:
char* Str; //pointer to string
int Str_s; // size of string public:
String(char* str = NULL);
~String();
void const print() const; //check
//~~~~~~~~~~~~~~~~~~
// operators
//~~~~~~~~~~~~~~~~~
String& operator=(const String& str);
bool operator==(const String& s) const;
bool operator!=(const String& s) const;
void operator-=(const char c);
void operator+=(const char c);
char& operator[](const int index) const;
//~~~~~~~~~~~~~~~~~~
// i/o ~~ operators
//~~~~~~~~~~~~~~~~~
friend ostream& operator<<(ostream&, const String& s);
friend istream& operator>>(istream&, String& s);
//~~~~~~~~~~~~~~~~~~
// arrange method
//~~~~~~~~~~~~~~~~~
void Letters(); // arrange all letter in sentence
void Space(); //remove all unwanted spaces
void Set_Str_s(int num) {
this->Str_s = num;
}
int Get_Str_s() {
return this->Str_s;
}
//~~~~~~~~~~~~~~~~~~
// methods
//~~~~~~~~~~~~~~~~~
char const* STR() {
return Str;
}
};
#endif
ostream& operator<<(ostream& output, const String& s) {
//char *c = s.Str;
//output << c << endl;
for (int i = 0; i < s.Str_s; i++) {
cout << s.Str[i];
}
return output;
}
istream& operator>>(istream& input, String& s) {
if (s.Str == NULL) {
s.Str_s = 0;
char temp[BUFFER];
int i = 0, j = 0;
cin.getline(temp, BUFFER);
while (temp[i] != NULL) {
s.Str_s++;
i++;
}
//s.Str = new char[s.Str_s];
s.Str = temp;
} else {
input >> s.Str;
}
return input;
}
#include <iostream>
using namespace std;
#include "string_head.h"
#include "Definition_head.h"
#include "Menu_head.h"
int main() {
char* c = "hi";
char* h = "lilo";
String s, m(c);
cin >> s;
cin >> m;
cout << s;
cout << endl;
cout << m;
}

Answer 1

The following line is a problem:
s.Str = temp;
you are storing a pointer to a local array that will be deleted when the function returns. Use something like:
s.Str = strdup(temp);
If your platform doesn't support strdup, you can implement it. It's not too hard.
The following line is also a problem:
input >> s.Str;
If there isn't enough memory to hold the string being read, you will be writing into memory that you are not supposed to.