How to use scanf in D ?

Or how to read integer and strings like in C with scanf ?

Örk

Örk wrote:
> How to use scanf in D ?
> Or how to read integer and strings like in C with scanf ?
> Örk

Here's some webpages that might be helpful:
http://www.digitalmars.com/rtl/stdio.html#fscanf
http://www.cplusplus.com/ref/cstdio/scanf.html


Here's an example in D:

import std.c.stdio;

int main()
{
	const int answer = 10;
	float guess;
	int i;
	char[80] name;


	printf("Yo! What's your name? ");
	scanf("%s", &name);

	printf("Pick a whole number: ");
	scanf("%d", &i);
	printf("You picked %d as a whole number.\n\n", i);
	
	printf("Guess a number: ");
	scanf("%f", &guess);

	printf("\nHey, %.*s, ", name);

	if(cast(int) guess <> answer)

	if(answer == guess)
		printf("answer = %f.", guess);
	else if(answer > guess)
		printf("answer > guess.");
	else if(answer < guess)
	{
		printf("answer < guess.");
	}
	else
		printf("Dude, that wasn't a number.");
	printf("\n");

	return 0;
}



-- 
Justin
http://jcc_7.tripod.com/d/

if(cast(int) guess <> answer)

?

is it vb uses that as a != operator ?

C

"J C Calvarese" <jcc7@cox.net> wrote in message news:btl20o$1id1$1@digitaldaemon.com...
> Örk wrote:
> > How to use scanf in D ?
> > Or how to read integer and strings like in C with scanf ?
> > Örk
>
> Here's some webpages that might be helpful: http://www.digitalmars.com/rtl/stdio.html#fscanf http://www.cplusplus.com/ref/cstdio/scanf.html
>
>
> Here's an example in D:
>
> import std.c.stdio;
>
> int main()
> {
> const int answer = 10;
> float guess;
> int i;
> char[80] name;
>
>
> printf("Yo! What's your name? ");
> scanf("%s", &name);
>
> printf("Pick a whole number: ");
> scanf("%d", &i);
> printf("You picked %d as a whole number.\n\n", i);
>
> printf("Guess a number: ");
> scanf("%f", &guess);
>
> printf("\nHey, %.*s, ", name);
>
> if(cast(int) guess <> answer)
>
> if(answer == guess)
> printf("answer = %f.", guess);
> else if(answer > guess)
> printf("answer > guess.");
> else if(answer < guess)
> {
> printf("answer < guess.");
> }
> else
> printf("Dude, that wasn't a number.");
> printf("\n");
>
> return 0;
> }
>
>
>
> --
> Justin
> http://jcc_7.tripod.com/d/

SQL does :\

In article <btlb1d$1vtl$1@digitaldaemon.com>, C says...
>
>if(cast(int) guess <> answer)
>
>?
>
>is it vb uses that as a != operator ?
>
>C
>
>"J C Calvarese" <jcc7@cox.net> wrote in message news:btl20o$1id1$1@digitaldaemon.com...
>> Örk wrote:
>> > How to use scanf in D ?
>> > Or how to read integer and strings like in C with scanf ?
>> > Örk
>>
>> Here's some webpages that might be helpful: http://www.digitalmars.com/rtl/stdio.html#fscanf http://www.cplusplus.com/ref/cstdio/scanf.html
>>
>>
>> Here's an example in D:
>>
>> import std.c.stdio;
>>
>> int main()
>> {
>> const int answer = 10;
>> float guess;
>> int i;
>> char[80] name;
>>
>>
>> printf("Yo! What's your name? ");
>> scanf("%s", &name);
>>
>> printf("Pick a whole number: ");
>> scanf("%d", &i);
>> printf("You picked %d as a whole number.\n\n", i);
>>
>> printf("Guess a number: ");
>> scanf("%f", &guess);
>>
>> printf("\nHey, %.*s, ", name);
>>
>> if(cast(int) guess <> answer)
>>
>> if(answer == guess)
>> printf("answer = %f.", guess);
>> else if(answer > guess)
>> printf("answer > guess.");
>> else if(answer < guess)
>> {
>> printf("answer < guess.");
>> }
>> else
>> printf("Dude, that wasn't a number.");
>> printf("\n");
>>
>> return 0;
>> }
>>
>>
>>
>> --
>> Justin
>> http://jcc_7.tripod.com/d/
>
>

C wrote:
> if(cast(int) guess <> answer)
Good catch.  It should be "!=" rather than "<>". I wonder if the compiler should flag that as an error.

> 
> ?
> 
> is it vb uses that as a != operator ?
Yes, I often speak BASIC.  (I used to make all kinds of weird mistakes when I was programming in Pascal and QBasic at the same time.)

> 
> C
> 
> "J C Calvarese" <jcc7@cox.net> wrote in message
> news:btl20o$1id1$1@digitaldaemon.com...
> 
>>Örk wrote:
>>
>>>How to use scanf in D ?
>>>Or how to read integer and strings like in C with scanf ?
>>>Örk
>>
>>Here's some webpages that might be helpful:
>>http://www.digitalmars.com/rtl/stdio.html#fscanf
>>http://www.cplusplus.com/ref/cstdio/scanf.html
>>
>>
>>Here's an example in D:
>>
>>import std.c.stdio;
>>
>>int main()
>>{
>>const int answer = 10;
>>float guess;
>>int i;
>>char[80] name;
>>
>>
>>printf("Yo! What's your name? ");
>>scanf("%s", &name);
>>
>>printf("Pick a whole number: ");
>>scanf("%d", &i);
>>printf("You picked %d as a whole number.\n\n", i);
>>
>>printf("Guess a number: ");
>>scanf("%f", &guess);
>>
>>printf("\nHey, %.*s, ", name);
>>
>>if(cast(int) guess <> answer)
>>
>>if(answer == guess)
>>printf("answer = %f.", guess);
>>else if(answer > guess)
>>printf("answer > guess.");
>>else if(answer < guess)
>>{
>>printf("answer < guess.");
>>}
>>else
>>printf("Dude, that wasn't a number.");
>>printf("\n");
>>
>>return 0;
>>}

-- 
Justin
http://jcc_7.tripod.com/d/

"<>" is a valid D operator,
equivalent to "!=" unless one or both of operands is a NaN.

"C" <dont@respond.com> wrote in message news:btlb1d$1vtl$1@digitaldaemon.com...
> if(cast(int) guess <> answer)
>
> ?
>
> is it vb uses that as a != operator ?
>
> C
>
> "J C Calvarese" <jcc7@cox.net> wrote in message news:btl20o$1id1$1@digitaldaemon.com...
> > Örk wrote:
> > > How to use scanf in D ?
> > > Or how to read integer and strings like in C with scanf ?
> > > Örk
> >
> > Here's some webpages that might be helpful: http://www.digitalmars.com/rtl/stdio.html#fscanf http://www.cplusplus.com/ref/cstdio/scanf.html
> >
> >
> > Here's an example in D:
> >
> > import std.c.stdio;
> >
> > int main()
> > {
> > const int answer = 10;
> > float guess;
> > int i;
> > char[80] name;
> >
> >
> > printf("Yo! What's your name? ");
> > scanf("%s", &name);
> >
> > printf("Pick a whole number: ");
> > scanf("%d", &i);
> > printf("You picked %d as a whole number.\n\n", i);
> >
> > printf("Guess a number: ");
> > scanf("%f", &guess);
> >
> > printf("\nHey, %.*s, ", name);
> >
> > if(cast(int) guess <> answer)
> >
> > if(answer == guess)
> > printf("answer = %f.", guess);
> > else if(answer > guess)
> > printf("answer > guess.");
> > else if(answer < guess)
> > {
> > printf("answer < guess.");
> > }
> > else
> > printf("Dude, that wasn't a number.");
> > printf("\n");
> >
> > return 0;
> > }
> >
> >
> >
> > --
> > Justin
> > http://jcc_7.tripod.com/d/
>
>

In article <btl20o$1id1$1@digitaldaemon.com>, J C Calvarese says...
>
>Örk wrote:
>> How to use scanf in D ?
>> Or how to read integer and strings like in C with scanf ?
>> Örk
>
>Here's some webpages that might be helpful: http://www.digitalmars.com/rtl/stdio.html#fscanf http://www.cplusplus.com/ref/cstdio/scanf.html
>
>
>Here's an example in D:
>
>import std.c.stdio;
>
>int main()
>{
>	const int answer = 10;
>	float guess;
>	int i;
>	char[80] name;
>
>
>	printf("Yo! What's your name? ");
>	scanf("%s", &name);

What happens here if the users enters a string longer than 80 characters?

Ian

> >int main()
> >{
> > const int answer = 10;
> > float guess;
> > int i;
> > char[80] name;
> >
> >
> > printf("Yo! What's your name? ");
> > scanf("%s", &name);
>
> What happens here if the users enters a string longer than 80 characters?
>
> Ian
>

It would write past the end, try this:
char[80] name;
printf("Yo! What's your name? ");
scanf("%79s", cast(char*)name);
printf("Your name is %s\n", cast(char*)name);

Hmm, when I compile this

import std.c.stdio;

void main () {

 if ( 0 <> 1 ) puts("true");

}

it fails with :

Assertion failure: '0' on line 487 in file 'constfold.c'

abnormal program termination

however != works fine.

?

C

"Robert" <no@spam.ne.jp> wrote in message news:btlsfh$2roq$1@digitaldaemon.com...
> "<>" is a valid D operator,
> equivalent to "!=" unless one or both of operands is a NaN.
>
> "C" <dont@respond.com> wrote in message news:btlb1d$1vtl$1@digitaldaemon.com...
> > if(cast(int) guess <> answer)
> >
> > ?
> >
> > is it vb uses that as a != operator ?
> >
> > C
> >
> > "J C Calvarese" <jcc7@cox.net> wrote in message news:btl20o$1id1$1@digitaldaemon.com...
> > > Örk wrote:
> > > > How to use scanf in D ?
> > > > Or how to read integer and strings like in C with scanf ?
> > > > Örk
> > >
> > > Here's some webpages that might be helpful: http://www.digitalmars.com/rtl/stdio.html#fscanf http://www.cplusplus.com/ref/cstdio/scanf.html
> > >
> > >
> > > Here's an example in D:
> > >
> > > import std.c.stdio;
> > >
> > > int main()
> > > {
> > > const int answer = 10;
> > > float guess;
> > > int i;
> > > char[80] name;
> > >
> > >
> > > printf("Yo! What's your name? ");
> > > scanf("%s", &name);
> > >
> > > printf("Pick a whole number: ");
> > > scanf("%d", &i);
> > > printf("You picked %d as a whole number.\n\n", i);
> > >
> > > printf("Guess a number: ");
> > > scanf("%f", &guess);
> > >
> > > printf("\nHey, %.*s, ", name);
> > >
> > > if(cast(int) guess <> answer)
> > >
> > > if(answer == guess)
> > > printf("answer = %f.", guess);
> > > else if(answer > guess)
> > > printf("answer > guess.");
> > > else if(answer < guess)
> > > {
> > > printf("answer < guess.");
> > > }
> > > else
> > > printf("Dude, that wasn't a number.");
> > > printf("\n");
> > >
> > > return 0;
> > > }
> > >
> > >
> > >
> > > --
> > > Justin
> > > http://jcc_7.tripod.com/d/
> >
> >
>

It seems to me that the Specification is unclear about this (http://www.digitalmars.com/d/expression.html), but <> seemed to be intended to be used with floating-point numbers (rather than integers such as 0 and 1).

That error message seems very vague.  (Might be a candidate for a bug report based on the error message if nothing else.)

Justin


In article <btmpmj$171k$1@digitaldaemon.com>, C says...
>
>Hmm, when I compile this
>
>import std.c.stdio;
>void main () {
> if ( 0 <> 1 ) puts("true");
>}
>
>it fails with :
>
>Assertion failure: '0' on line 487 in file 'constfold.c'
>abnormal program termination
>however != works fine.
>?
>C