#Help in String class

6 messages · Page 1 of 1 (latest)

random ferry
#

I'm trying to make custom string class,
everything is working fine in this but when i take input then it is not printing any line after that it just ends the program

#include<bits/stdc++.h>
using namespace std;

class String
{
    char *ch;            // buffer
    unsigned int len;    // to store the length
    public:
    // default constructor
        String() : ch(nullptr) , len(0){};

    // parametrized constructor
    String(const char *str)
    {
        len = strlen(str+1);
        ch = new char[len+1];
        strcpy(ch,str);      // (to , from)
    }


    // copy constructor
    String(const String& str)
    {
        this->ch = str.ch;
        len = strlen(ch+1);
    }

    // assignment operator overloading
    String &operator=(String str)
    {
        if(this->ch != str.ch)
        {
            Swap(*this,str);
        }
        return *this;
    }

    void Swap(String &a, String &b){
        std::swap(a.ch,b.ch);
        std::swap(a.len,b.len);
    }

    friend ostream &operator<<(ostream &out , const String &str);
    friend istream &operator>>(istream &in ,  String &str);
};


ostream &operator<<(ostream &out , const String &str)
{
    out<<str.ch;
    return out;
}

istream &operator>>(istream &in , String &str)
{
    in>>str.ch;
    return in;
}

int main()
{
    String myString = "hello";
    // cin>>myString;
    cout<<myString<<endl;
    String sty ;
    sty = myString;
    cout<<sty<<endl;
    String hup;
    cin>>hup;
    cout<<hup<<endl;
}
wooden marshBOT
#

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random ferry
#

plz mention

frail panther
#

@random ferry you should take this question to #1013107104678162544 instead.

#

I've not looked to carefully, but could it be that internally your String class is not null-terminated?
If so then you may need something like this instead

ostream &operator<<(ostream &out , const String &str)
{
    out.write(str.ch, str.len);
    // you may still want to append the null terminator here though?
    return out;
}
#

Your input stream looks wrong too.
You cannot just stream to a char*.

Without cheating via istream::getline() you'd have to read ahead in the stream to find the null terminator, do the memory allocation to however many bytes you skipped ahead to get there, and then play catch-up from the rear to actually read the string into yours.