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assign string to chr*

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  assign string to chr* cerr <ron.eggler@gmail.com> - 2011-07-28 19:50 -0700
    Re: assign string to chr* Ian Collins <ian-news@hotmail.com> - 2011-07-29 15:12 +1200
    Re: assign string to chr* Juha Nieminen <nospam@thanks.invalid> - 2011-07-29 06:09 +0000
    Re: assign string to chr* MJ_India <mail.mohitjain@gmail.com> - 2011-07-29 23:30 -0700
    Re: assign string to chr* Sasha Daje <sasha.daje@gmail.com> - 2011-07-30 15:11 -0700
      Re: assign string to chr* Ian Collins <ian-news@hotmail.com> - 2011-07-31 10:35 +1200
        Re: assign string to chr* James Kanze <james.kanze@gmail.com> - 2011-08-07 10:30 -0700
          Re: assign string to chr* Ian Collins <ian-news@hotmail.com> - 2011-08-08 07:39 +1200
    Re: assign string to chr* "xieyuntian" <xieyuntian1981@sohu.com> - 2011-08-02 17:37 +0800
    Re: assign string to chr* SG <s.gesemann@gmail.invalid> - 2011-08-09 11:36 +0200

#8305 — assign string to chr*

hi,

how do i correctly assign a string to a char*?
If i do it
char *test;
test= "BLABLA";
I get "warning: deprecated conversion from string constant to ‘char*’"
But strcpy() ot sprintf() doesn't work because there's no room
allocated yet. So do I actually need to allocate space with calloc()/
malloc()?
Thanks,
Ron

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#8306

On 07/29/11 02:50 PM, cerr wrote:
> hi,
>
> how do i correctly assign a string to a char*?
> If i do it
> char *test;
> test= "BLABLA";
> I get "warning: deprecated conversion from string constant to ‘char*’"
> But strcpy() ot sprintf() doesn't work because there's no room
> allocated yet. So do I actually need to allocate space with calloc()/
> malloc()?

Either use std::string, const char* or char[].

-- 
Ian Collins

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#8309

cerr <ron.eggler@gmail.com> wrote:
> how do i correctly assign a string to a char*?
> If i do it
> char *test;
> test= "BLABLA";
> I get "warning: deprecated conversion from string constant to ???char*???"

  Try to read the message. The crucial keyword is "constant".
(Hint: your 'test' variable isn't.)

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#8326

On Jul 29, 11:50 am, cerr <ron.egg...@gmail.com> wrote:
> hi,
>
> how do i correctly assign a string to a char*?
> If i do it
> char *test;
> test= "BLABLA";
> I get "warning: deprecated conversion from string constant to ‘char*’"
> But strcpy() ot sprintf() doesn't work because there's no room
> allocated yet. So do I actually need to allocate space with calloc()/
> malloc()?
> Thanks,
> Ron

Are you sure you want _editable_ pointer to char?
1. If yes, you can avoid malloc/new etc and allocate space on stack or
use std::string for automatic allocation and free.
char *test;
char blabla[] = "BLABLA";
test= blabla;
2. If no, replace
char *test;
with
const char *test;
or
char const *test;
as per your preferred coding style.

-Mohit

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#8344

test = (char*)"BLABLA";

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#8345

On 07/31/11 10:11 AM, Sasha Daje wrote:

Context?

> test = (char*)"BLABLA";

No you don't want to do that if test is a char*.

-- 
Ian Collins

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#8544

On Jul 30, 11:35 pm, Ian Collins <ian-n...@hotmail.com> wrote:
> On 07/31/11 10:11 AM, Sasha Daje wrote:

> Context?

> > test = (char*)"BLABLA";

> No you don't want to do that if test is a char*.

It depends on where test is defined.  I've recently written a
lot of code full of const_cast<char*>.  I had to interface with
a third party library written in C, which didn't use const (or
only rarely used const).

--
James Kanze

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#8555

On 08/ 8/11 05:30 AM, James Kanze wrote:
> On Jul 30, 11:35 pm, Ian Collins<ian-n...@hotmail.com>  wrote:
>> On 07/31/11 10:11 AM, Sasha Daje wrote:
>
>> Context?
>
>>> test = (char*)"BLABLA";
>
>> No you don't want to do that if test is a char*.
>
> It depends on where test is defined.  I've recently written a
> lot of code full of const_cast<char*>.  I had to interface with
> a third party library written in C, which didn't use const (or
> only rarely used const).

But you didn't do that with string literals, did you?

-- 
Ian Collins

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#8401

"cerr" <ron.eggler@gmail.com> 
??????:f1a1a754-4b33-4c69-9ed4-73ab46c07bb7@d8g2000prf.googlegroups.com...
hi,

how do i correctly assign a string to a char*?
If i do it
char *test;
test= "BLABLA";
I get "warning: deprecated conversion from string constant to ‘char*’"
But strcpy() ot sprintf() doesn't work because there's no room
allocated yet. So do I actually need to allocate space with calloc()/
malloc()?
Thanks,
Ron

VS2008 VS2005, no warning



--- Posted via news://freenews.netfront.net/ - Complaints to news@netfront.net ---

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#8582

Am 29.07.2011 04:50, schrieb cerr:
> how do i correctly assign a string to a char*?
> If i do it
> char *test;
> test= "BLABLA";
> I get "warning: deprecated conversion from string constant to ‘char*’"
> But strcpy() ot sprintf() doesn't work because there's no room
> allocated yet. So do I actually need to allocate space with calloc()/
> malloc()?
> Thanks,
> Ron

Hello Ron,

I don't feel like you understand what `test` -- the way you declared it 
-- actually is.  This is because you're speaking of assigning a string 
to `char*`.  But a variable with a type `char*` does not store strings. 
It stores addresses. So, you can only assign some address to it. While 
it is possible to use a string literal on the right hand side of such an 
assignment, what you really assign to test is an address, in this case, 
the address of the first character.

I suggest you try to explain your higher level goal instead.  Why do you 
want to use a pointer?  What for?  If this is really what you want: 
Where do you want this pointer to point to?

If you want to declare a variable that is able to STORE string VALUES 
much like an int variable is able to STORE some integer VALUE or a 
double variable is able to STORE an approximation of a real VALUE, 
`char*` is not the type you want but `std::string` is.

Nobody likes dealing with dynamic memory for string handling manually. 
Some may say they do but I wouldn't believe them. ;-) Luckily, in C++ 
there are nicer alternatives. Consider getting a decent C++ book (like 
Accelerated C++) so you can take advantage of the things that C++ has to 
offer.

SG

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