are strings passed by value or reference ? Output of below pgm not understood.

[plshaji]

Are strings passed by value or reference?

I don't understand the output of below program.

#include<iostream.h>
void print(char *p)
{
    p="Pass";
    cout<<"\n value is :"<<p;
}
void main()
{
    clrscr();
    char *q="Best of Luck";
    print(q);
    cout<<"\n New Value is : "<<q;
 
}

The answer is displayed as follows ...
The value is : Pass
New Value is : Best of Luck

Isn't a string passed by reference? Pls explain the reason for this answer .

[weaknessforcats]

First, everything is passed by value. When you use q to call a function, the function makes a copy called p and assigns the address of "Pass" to p. Now you see p displayed as Pass. Then p is destroyed when the function returns. The calling function uses q in a display and you see Best of Luck.

Nothing is passed by reference unless you use the reference operator with your function argument.

As to strings, a char* is not a string. An old C convention was used to ASSUME a char* was the address of a char array whose last byte was a null (\0).

A C++ string is a class:

string str;

To use C++ strings you need to study the C++ Standard Library string class.