digitalmars.D.bugs - toString()???
- Ozy (35/36) Aug 11 2004 Hello, there.
- J C Calvarese (46/89) Aug 11 2004 Interesting, but not entirely unexpected.
- h3r3tic (18/32) Aug 11 2004 Hiya, your programs has several programs... you're using char* to point
- Derek Parnell (20/61) Aug 11 2004 If the integer is from 0 to 9, the toString() routine returns a slice in...
- Ozy (9/9) Aug 11 2004 I see.
Hello, there.
I was using function "toString()", and found...
/* test.d */
import std.c.stdio;
import std.stream;
char* str;
void main(){
for(int i=0; i<20; ++i){
str = toString(i);
printf("n=%s\n",str);
}
return;
}
/* end test.d */
result:
test
n=0123456789
n=123456789
n=23456789
n=3456789
n=456789
n=56789
n=6789
n=789
n=89
n=9
n=10
n=11
n=12
n=13
n=14
n=15
n=16
n=17
n=18
n=19
Aug 11 2004
J C Calvarese <jcc7 cox.net>
Ozy wrote:
Hello, there.
I was using function "toString()", and found...
/* test.d */
import std.c.stdio;
import std.stream;
char* str;
void main(){
for(int i=0; i<20; ++i){
str = toString(i);
printf("n=%s\n",str);
}
return;
}
/* end test.d */
result:
test
n=0123456789
n=123456789
n=23456789
n=3456789
n=456789
n=56789
n=6789
n=789
n=89
n=9
n=10
n=11
n=12
n=13
n=14
n=15
n=16
n=17
n=18
n=19
Interesting, but not entirely unexpected.
This might be what you want:
/* test.d */
import std.c.stdio;
import std.stream;
char[] str;
/* I wouldn't use a char* unless I had to. */
void main(){
for(int i=0; i<20; ++i){
str = toString(i);
printf("n=%.*s\n",str);
/* "%.*s" is the specifier for char[]*/
}
return;
}
/* end test.d */
n=0
n=1
n=2
n=3
n=4
n=5
n=6
n=7
n=8
n=9
n=10
n=11
n=12
n=13
n=14
n=15
n=16
n=17
n=18
n=19
There are a couple reasons for this:
1) toString expects to to return a char[].
2) Weird things can happen when strings are sent to printf without a
trailing \0.
For some more interesting examples, see:
http://www.prowiki.org/wiki4d/wiki.cgi?HowTo/printf
--
Justin (a/k/a jcc7)
http://jcc_7.tripod.com/d/
Aug 11 2004
Ozy wrote:
/* test.d */
import std.c.stdio;
import std.stream;
char* str;
void main(){
for(int i=0; i<20; ++i){
str = toString(i);
printf("n=%s\n",str);
}
return;
}
/* end test.d */
Hiya, your programs has several programs... you're using char* to point
to a string. after doing str=toString() you loose the length of the
string and you cant give it thru %.*s to printf. and you give it thru
normal %s which doesnt work with D strings...
The solution is damn simple, though :]
!(code)
import std.stdio;
void main()
{
for (int i = 0; i < 20; ++i)
{
writefln("n=", i);
}
}
!(/code)
printf should be depreceated for new code imo ;)
Tom
Aug 11 2004
On Thu, 12 Aug 2004 11:51:18 +0900, Ozy wrote:
Hello, there.
I was using function "toString()", and found...
/* test.d */
import std.c.stdio;
import std.stream;
char* str;
void main(){
for(int i=0; i<20; ++i){
str = toString(i);
printf("n=%s¥n",str);
}
return;
}
/* end test.d */
result:
test
n=0123456789
n=123456789
n=23456789
n=3456789
n=456789
n=56789
n=6789
n=789
n=89
n=9
n=10
n=11
n=12
n=13
n=14
n=15
n=16
n=17
n=18
n=19
If the integer is from 0 to 9, the toString() routine returns a slice into
a static array. The correct way to use the return value from toString is
more like this ...
import std.c.stdio;
import std.stream;
char[] str; // NOT char*;
void main(){
for(int i=0; i<20; ++i)
{
str = toString(i);
printf("n=%.*s\n",str); // NOT %s but %.*s
}
return;
}
/* end test.d */
--
Derek
Melbourne, Australia
12/Aug/04 1:48:11 PM
Aug 11 2004
I see. Then, if I use C-Library, should I write like this? char[2] str; str[0] = toString(0-9numeral)[0]; str[1] ='\0'; c_func(str); It's troublesome for me... Anyway, I understood that this problem is not a bug. Thank you very much!
Aug 11 2004
"Ozy" <ozy 4dm.org> wrote in message news:cfeu67$1pk3$1 digitaldaemon.com...I see. Then, if I use C-Library, should I write like this? char[2] str; str[0] = toString(0-9numeral)[0]; str[1] ='\0'; c_func(str); It's troublesome for me... Anyway, I understood that this problem is not a bug. Thank you very much!char[] dstr; char* cstr; dstr = toString(9); cstr = toStringz(dstr); // zero terminate c_func(cstr); // hooray
Aug 11 2004