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delete

Started by yummy_potatoes Mar 14, 2003 at 11:42 PM 3 replies 200+ views

Original Post

Mar 14, 2003 at 11:42 PM

I feel stupid for even asking this, but I skimmed through my c++ book, and it doesn't seem to have an example of this: My Question:

    
int *a, *b;
a = new int[50];
b = new int[50];

/////////////////////////////////////////

// Are both of these methods of deletion the same?

/////////////////////////////////////////


delete [] a;
delete [] b;

//or this method

delete [] a, b;

[edited by - yummy_potatoes on March 14, 2003 12:43:58 AM]

Beer Hunter

Mar 15, 2003 at 12:32 AM

Short answer: No.

Long answer: The comma is used for two purposes: separating parameters, and as a binary operator. As a binary operator, it returns the right-hand value. When you write delete[] a, b;, the comma is considered as a binary operator, returning b and doing nothing with a. Therefore, only b will be deleted.

SiCrane

Mar 15, 2003 at 1:14 AM

quote:
Original post by Beer Hunter
When you write delete[] a, b;, the comma is considered as a binary operator, returning b and doing nothing with a. Therefore, only b will be deleted.

Almost right -- you forgot operator precedence. delete [] a, b will be parsed as (delete [] a), b

So only a will be delete []''d and the expression will return b.

Beer Hunter

Mar 15, 2003 at 2:27 AM

Quite right. Sorry for any confusion I caused.

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