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Re: !foo vs foo == nil
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Re: !foo vs foo == nil


  • Subject: Re: !foo vs foo == nil
  • From: "mm w" <email@hidden>
  • Date: Wed, 20 Aug 2008 19:44:47 -0700

Using NULL would make your code easier to read, setting
a variable to NULL makes it obvious that a variable is a pointer,
at least in C, NULL does not have to be 0, 0 could be a valid pointer
value*, and NULL
some other invalid value, many people got in the habit of writing

if (!foo)

sure the compiler will automagically convert 0 in a pointer context to
an invalid pointer value,
plus preprocessor turns NULL back into 0 which is then recognized by the it

using NULL or nil (ObjC) is the recommended way, when referring to a pointer

for the tip an uninitialized variable is not really nothing

On Wed, Aug 20, 2008 at 6:50 PM, Quincey Morris
<email@hidden> wrote:
> On Aug 20, 2008, at 18:15, mm w wrote:
>
>> as a previous oppenant said yeh dude it's normal it's undefined/ nothin
>> nada :)
>>
>> int main(void) {g
>>     char *p1;
>>     char *p2 = NULL;
>>
>>     if(!p1)
>>        puts("hello p1");
>>
>>     if(!p2)
>>        puts("hello p2");
>>
>>     return 0;
>> }
>>
>> output "hello p2"
>
> I not sure of the state of computer science on planet Neptune, but here on
> Earth we pretty much grasped the concept of an uninitialized variable about
> 50 years ago.
>
>
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--
-mmw
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  • Follow-Ups:
    • Re: !foo vs foo == nil
      • From: "Clark Cox" <email@hidden>
References: 
 >!foo vs foo == nil (From: Torsten Curdt <email@hidden>)
 >Re: !foo vs foo == nil (From: "mm w" <email@hidden>)
 >Re: !foo vs foo == nil (From: Andrew Merenbach <email@hidden>)
 >Re: !foo vs foo == nil (From: "mm w" <email@hidden>)
 >Re: !foo vs foo == nil (From: "mm w" <email@hidden>)
 >Re: !foo vs foo == nil (From: Quincey Morris <email@hidden>)

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