function is returning junk data

Question

I am trying this program

#include<iostream>
#include<string.h>

class stringTest
{
    char* p;
    int len;
public:
    stringTest() { len = 0; p = 0; }
    stringTest(const char* s);
    stringTest(const stringTest& s);
    ~stringTest() { delete p; }

    friend stringTest operator+(const stringTest& s, const stringTest& t);
    friend int operator<=(const stringTest& s, const stringTest& t);
    friend void show(const stringTest s);
};

stringTest::stringTest(const char* s)
{
    len = strlen(s);
    p = new char[len + 1];
    strcpy(p, s);
}
stringTest::stringTest(const stringTest& s)
{
    len = s.len;
    p = new char[len + 1];
    strcpy(p, s.p);
}

stringTest operator+(const stringTest &s, const stringTest &t)
{
    stringTest temp;
    temp.len = s.len + t.len;
    temp.p = new char[temp.len + 1];
    strcpy(temp.p, s.p);
    strcat(temp.p, t.p);
    return (temp);
}
int operator<=(const stringTest& s, const stringTest& t)
{
    int m = strlen(s.p);
    int n = strlen(t.p);

    if (m <= n) return (1);
    else return (0);
}

void show(const stringTest s)
{
    cout << s.p;
}


int main()
{
    stringTest s1 = "New ";
    stringTest s2 = "York";
    stringTest s3 = "Delhi";
    stringTest string1, string2, string3;
    string1 = s1;
    string2 = s2;
    string3 = s1+s2;

    cout << "\nstirng1 = "; show(string1);
    cout << "\nstring2 = "; show(string2);
    cout << "\n";
    cout << "\nstring3 = "; show(string3);
    cout << "\n\n";
    if (string1 <= string3)
    {
        show(string1);
        cout << " smaller than ";
        show(string3);
        cout << "\n";
    }
    else
    {
        show(string3);
        cout << " smaller than ";
        show(string1);
        cout << "\n";
    }
    return 0;
}

here in the function operator+ I am providing two string and getting an junk character in return.

stringTest operator+(const stringTest &s, const stringTest &t)
{
    stringTest temp;
    temp.len = s.len + t.len;
    temp.p = new char[temp.len + 1];
    strcpy(temp.p, s.p);
    strcat(temp.p, t.p);
    return (temp);
}

I debugged the code and saw in the memory i am able to get the proper data in temp.p but when i return it become junk character . Please help me if i am missing something.

Thanks in advance

Vivek

Why all this manual memory management and mucking around with `char*`? Why not just use `std::string`? — Jesper Juhl, Dec 12 '22 at 14:47
You forgot the assignment operator. Have a look into the [rule of 3/5/0](https://en.cppreference.com/w/cpp/language/rule_of_three). — rustyx, Dec 12 '22 at 14:52
C++ provides `std::string`, which has been highly scrutinized, thoroughly debugged, very performant, and interops with the other parts of C++ (like the standard C++ library file system or regular expression facilities). — Eljay, Dec 12 '22 at 15:03
To add, `std::string` has been part of C++ for 24 years. If you are not aware of how to make a class correctly copyable and assignable (which yours is not one), then stick with using `std::string`. — PaulMcKenzie, Dec 12 '22 at 15:14

function is returning junk data

0 Answers0