question about 'operator new'

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Started by BASSOFeeSH June 05, 2000 09:52 PM

4 comments, last by BASSOFeeSH 24 years, 9 months ago

BASSOFeeSH

Author

122

June 05, 2000 09:52 PM

here is the code:

    
int main()
{
     char *name = NULL;
     name = new char[11];

     cout << strlen(name);

     return 0;
}

The output of strlen is 15? I don't get it. Is this just because of random garbage in memory? "If at first you DO succeed...try not to look astonished!!" BASSOFeeSH@aol.com BASSOFeeSH ><> Edited by - Michael Tanczos on 6/5/00 11:10:18 PM

-- What would Sweetness do?

Muzzafarath

146

June 06, 2000 02:37 AM

Yes, it's because of "random garbage". Since you are dynamically allocating the memory, there is no guarantee that the memory will be set to zero.

To get the desired result (0), you must set the first place of name to \0.

    int main(){char *name = NULL;name = new char[11];name[0] = '\0';cout << strlen(name);return 0;}

There is usually no need to do this, since you will probably use string functions (such as strcpy() or gets()) that will make sure that the \0 is at the correct place, before you use the strlen() function.

/. Muzzafarath
Mad House Software

Edited by - Muzzafarath on June 6, 2000 12:26:51 PM

I'm reminded of the day my daughter came in, looked over my shoulder at some Perl 4 code, and said, "What is that, swearing?" - Larry Wall

Nazrix

307

June 06, 2000 09:51 AM

Unrelated Q
How''d you guys put the code into that neat white background?

Need help? Well, go FAQ yourself. "Just don't look at the hole." -- Unspoken_Magi

Muzzafarath

146

June 06, 2000 11:05 AM

It's easy Nazrix, put all code in [ source] code goes here [ /source] blocks (without the spaces in the tags).

                    int main(void){int i;for(i = 0; i < 5000; i++){printf("%d\n", i);}return 0;}

I noticed that it doesn't color void when it's inside ()... Weird.

/. Muzzafarath
Mad House Software

Edited by - Muzzafarath on June 6, 2000 12:24:09 PM

I'm reminded of the day my daughter came in, looked over my shoulder at some Perl 4 code, and said, "What is that, swearing?" - Larry Wall

Nazrix

307

June 06, 2000 12:09 PM

                    #include <stdio.h>                    int main ( void ){puts("Hey that's cool! Thanks.");}

PS Muzzafarath, if you put void with spaces around it, it is blue...just figured that out

Edited by - Nazrix on June 6, 2000 1:50:30 PM

Need help? Well, go FAQ yourself. "Just don't look at the hole." -- Unspoken_Magi

SHilbert

652

June 06, 2000 12:54 PM

    int Sprite::DistanceTo( Sprite *s ){	return (int)Distance(x,y,s->x,s->y);}

Cool...

lntakitopi@aol.com | http://geocities.com/guanajam/

question about 'operator new'

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question about 'operator new'

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