problem encountered while doing mathematical operations on strings by overloaded '+'.

[Tarun Jha]

#include
#include
using namespace std;

class st{

char \*p;
int len;

public:
	st(){len=0; p=0;}		//creates null string
	st(const char \*s);		//creates string from arrays
	st(const st &s);		//copy constructor
	~st(){delete p;}		//destructor

	//+ operator
	friend st operator + (const st &, const st &);

	//<= operator
	friend int operator <= (const st &, const st &);
	friend void show(const st);

};

st :: st(const char *s){
len = strlen(s);
p = new char[len+1];
strcpy(p, s);
//cout<

This program works fine when i replace

Quote:

st string1, string2, string3;

with

Quote:

st string1=s1, string2=s2, string3=s1+s3;

so what's the problem, i learned in class that we can pass the values in the constructor by calling it explicitly, and (string1, string2, string3) & (s1, s2, s3) have same return type i.e.class st.
So why isn't it working ?

thank you

[Victor Nijegorodov]

To make this part of code working:

st string1, string2, string3;
string1 = s1;
string2 = s2;

you must implement the assignment operator for your class st.

[CPallini]

As Victor Nijegorodov noted, your code violates the rule of three[^]: you have to define the assignment operator.