Doubt relating to delete operator :(

[chottachatri]

Hello,
i am little confused while i use delete operator. I am posting my code :-

#include"iostream.h"
#include"string.h"

class str
{
   char *p;
   public:
	  str(char *t)
	  {
		  p=new char[strlen(t)+1];
		  strcpy(p,t);
	  }
	  ~str()
	  {
		  delete []p;
	  }
	  void putdata()
	  {
		  cout<<p;
	  }
};

int main(void)
{
 str t("Hello World");
 t.putdata();
 cin.ignore();
 cin.get();
 return 0;
}

In the above code i am confused as to whether i should use delete []p or i should use only p??None of them gives any syntactical error but i am confused i feel i should be delete []p but in Balagurusamy's book its given delete p.

Also please try to explain in a clear cut manner like when i use double dimension array then what i should i write in delete???Please help me?

[vart]

when you have new[] you use delete[]

so in this case delete[] will be appropriate

#include"iostream.h"
#include"string.h"

should be

#include <iostream>
#include <cstring>

also you need to use std namespace - your compiler is outdated

Your class as working with dynamic memory allocations has missing copy-constructor and operator=

[chottachatri]

Ok now please tell me how to deallocate memory for two dimensional array?Is this the correct way of doing it?

for(int i=0;i<rows;i++)
    delete []a[i];

where a is the 2 dimensional array and rows is the total number of rows!??

[anon]

And you'll need to delete[] a after that.

However, unless you are required to do it this way, you should use std::string (for strings) and std::vector (for dynamic arrays), as they will take care of memory management automatically, and your class probably won't need a user-defined destructor, copy constructor and assignment operator.