char & wchar_t

[Samant.Trupti]

Hi,

There is one thing I am cofused about....
If I have a declareation say

char str[10];
Now if I want to change it to wchar so do I have to change it
like ....

wchar_t str[10]; or double the size? like
wchar_t str[20];

if yes then Why? char and wchar_t wont take care of it?

Thanks
TS

 

[Ian Collins]

Hi,

There is one thing I am cofused about....
If I have a declareation say

char str[10];
Now if I want to change it to wchar so do I have to change it
like ....

wchar_t str[10]; or double the size? like
wchar_t str[20];

The array size is the number of elements of that type. char str[10] is
an array of 10 char, wchar_t str[10] is an array of 10 wchar_t.

 

[Samant.Trupti]

Hi,

  There is one thing I am cofused about....
If I have a declareation say

   char str[10];
Now if I want to change it to wchar so do I have to change it
like ....

  wchar_t str[10];  or double the size? like
  wchar_t str[20];

The array size is the number of elements of that type.  char str[10] is
an array of 10 char, wchar_t str[10] is an array of 10 wchar_t.

Ok Good this is what I was thinking. Wanted confirm. Thank you.

 

[dertopper]

Hi,

  There is one thing I am cofused about....
If I have a declareation say

   char str[10];
Now if I want to change it to wchar so do I have to change it
like ....

  wchar_t str[10];  or double the size? like
  wchar_t str[20];

if yes then Why? char and wchar_t wont take care of it?

They will. Note that you only specify the number of elements of the
array, not the number of bytes. Thus sizeof(char[10]) == 10, but
sizeof(wchar_t[10]) == 20!
It only gets more troublesome if you are using utf8 characters that
need more than one byte (though doubling the arrays will only lead to
unused space).

Regards,
Stuart

 

[Samant.Trupti]

Hi,

  There is one thing I am cofused about....
If I have a declareation say

   char str[10];
Now if I want to change it to wchar so do I have to change it
like ....

  wchar_t str[10];  or double the size? like
  wchar_t str[20];

if yes then Why? char and wchar_t wont take care of it?

They will. Note that you only specify the number of elements of the
array, not the number of bytes. Thus sizeof(char[10]) == 10, but
sizeof(wchar_t[10]) == 20!
It only gets more troublesome if you are using utf8 characters that
need more than one byte (though doubling the arrays will only lead to
unused space).

Regards,
Stuart

Well then your suggesion would be double the size?? When I declare
char it is one byte and wchar_t it is 2 bytes, isn't that true?
So when I say char[10] it is 10 bytes so wchar_t[10] should be 20
bytes right??
Thanks
TS

 

[Greg Herlihy]

  There is one thing I am cofused about....
If I have a declareation say
   char str[10];
Now if I want to change it to wchar so do I have to change it
like ....
  wchar_t str[10];  or double the size? like
  wchar_t str[20];
if yes then Why? char and wchar_t wont take care of it?

They will. Note that you only specify the number of elements of the
array, not the number of bytes. Thus sizeof(char[10]) == 10, but
sizeof(wchar_t[10]) == 20!
It only gets more troublesome if you are using utf8 characters that
need more than one byte (though doubling the arrays will only lead to
unused space).

Well then your suggesion would be double the size?? When I declare
char it is one byte and wchar_t it is 2 bytes, isn't that true?
So when I say char[10] it is 10 bytes so wchar_t[10] should be 20
bytes right??

Not necessarily. On some systems (OS X comes to mind) the size of
wchar_t is four bytes. In that case, a wchar_t[10] array requires 40
bytes of storage - or quadruple the amount of memory needed to store a
char[10] array..

Greg