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digitalmars.D - Newbie: Outputting non char types

reply matthew_hurne yahoo.com writes:
As simple as you all probably think this is, I could use a hand...

First of all, what is the best way to do standard output?  I.e. the equivalent
of Java's System.out or C++'s cout?  Is it writefln?  stdout.write()?  Or what?

Secondly, how can I output simple types such as ints or doubles?  I found
std.format, but that is a bit over my head at this point, probably because I
haven't learned too much about this language yet.  But the truth is, if that's
how it must be done than I can't see how D is so much easier to use than C++.
Please tell me there's an easier way!  I did try stdout.write(doubleVar) and it
printed junk...probably something to do with "the format is
implementation-specific and should only be used in conjunction with read" ...
I'm guess that would work fine if I were say, saving these to a file to be read
back in later.  But I want them output on the terminal.

Oh, I'm using Linux, btw.

Thanks in advance for any tips.  If this is covered at some online tutorial or
something and you just want to point me there, feel free!
Nov 19 2004
parent reply J C Calvarese <jcc7 cox.net> writes:
In article <cnlkrh$qn0$1 digitaldaemon.com>, matthew_hurne yahoo.com says...

As simple as you all probably think this is, I could use a hand...

First of all, what is the best way to do standard output?  I.e. the equivalent
of Java's System.out or C++'s cout?  Is it writefln?  stdout.write()?  Or what?


If you just want to send text to the screen, I think the best way is
writef/writefln in std.stdio.


Secondly, how can I output simple types such as ints or doubles?  I found
std.format, but that is a bit over my head at this point, probably because I
haven't learned too much about this language yet.  But the truth is, if that's
how it must be done than I can't see how D is so much easier to use than C++.
Please tell me there's an easier way!  I did try stdout.write(doubleVar) and it
printed junk...


You need to use a format string (%s is a sort of the default specifier)...
writefln("%s", i);

Here's the nitty-gritty details:
http://www.digitalmars.com/d/std_format.html#format-string


Thanks in advance for any tips.  If this is covered at some online tutorial or
something and you just want to point me there, feel free!


Here's an example:
http://www.dsource.org/tutorials/index.php?show_example=105

By the way, D still has printf. printf isn't as easy to use as writef/writefln,
but there are more examples of how to use it out there, such as:
http://www.prowiki.org/wiki4d/wiki.cgi?HowTo/printf

It's not that I recommend using printf, but if you're having trouble grasping
the idea of writef/writefln's format string, printf's format string concept is
similar. It might be easier to learn printf just because there are more examples
around using it.

jcc7
Nov 19 2004
parent reply matthew_hurne yahoo.com writes:
In article <cnlltm$s3k$1 digitaldaemon.com>, J C Calvarese says...

In article <cnlkrh$qn0$1 digitaldaemon.com>, matthew_hurne yahoo.com says...

As simple as you all probably think this is, I could use a hand...

First of all, what is the best way to do standard output?  I.e. the equivalent
of Java's System.out or C++'s cout?  Is it writefln?  stdout.write()?  Or what?


If you just want to send text to the screen, I think the best way is
writef/writefln in std.stdio.


Thanks for that tip...



Secondly, how can I output simple types such as ints or doubles?  I found
std.format, but that is a bit over my head at this point, probably because I
haven't learned too much about this language yet.  But the truth is, if that's
how it must be done than I can't see how D is so much easier to use than C++.
Please tell me there's an easier way!  I did try stdout.write(doubleVar) and it
printed junk...


You need to use a format string (%s is a sort of the default specifier)...
writefln("%s", i);


Thank God, I thought I was going to have to use that doFormat function...when I
referred to not understanding something in the above, that's the function I was
having trouble with.  Sorry that I didn't make the connection that you can use
format strings with writef and writefln.



Here's the nitty-gritty details:
http://www.digitalmars.com/d/std_format.html#format-string


Thanks in advance for any tips.  If this is covered at some online tutorial or
something and you just want to point me there, feel free!


Here's an example:
http://www.dsource.org/tutorials/index.php?show_example=105

By the way, D still has printf. printf isn't as easy to use as writef/writefln,
but there are more examples of how to use it out there, such as:
http://www.prowiki.org/wiki4d/wiki.cgi?HowTo/printf

It's not that I recommend using printf, but if you're having trouble grasping
the idea of writef/writefln's format string, printf's format string concept is
similar. It might be easier to learn printf just because there are more examples
around using it.

jcc7


So here's a question...what if I wanted to actually output %s?  \%s doesn't
work...honestly I think this question is pretty irrelevant but I'm curious.  :-)
Thanks for the help!
Nov 19 2004
parent Thomas Kuehne <thomas-dloop kuehne.thisisspam.cn> writes:
matthew_hurne yahoo.com schrieb am Fri, 19 Nov 2004 20:51:41 +0000 (UTC):

 So here's a question...what if I wanted to actually output %s?  \%s doesn't
 work...honestly I think this question is pretty irrelevant but I'm curious. 
:-)
 Thanks for the help!


"%%s" -> "%s"

Thomas
Nov 19 2004