Keean Schupke wrote:
> At the risk of getting off topic... the reason 'C' has printf is because > it is not polymorphic. Printf is a hack to allow different types to be > printed out, such that they did not need printInt, printFloat etc.
Many language have printf-like functions despite not satisfying this criterion. Perl, Python, and Common Lisp are the three that come to mind.
I think the reason they have it is that it's useful in general to be able to visually separate the string template from the expressions being printed. Even (name++", your age is"++age++".") is pretty punctuation-heavy for a template. (Plus, it has a bug in it, which would be much easier to see in the printf syntax.)
Perl, as I see it, has printf for two reasons. The first is because sometimes
printf "something%dsomething else", $number;
is nicer to deal with than
print "something${number}something else";but I think primarily because printf lets you specify the number formatting and other such things, which Perl's variable interpolation system won't. Things like
printf "%02d", $number;
Are invaluable at times. That, as I see it, is the value of printf-like functions. It's certainly preferable (no matter how painful to the parts of us which like nice clean pure code) to C++'s rather unpleasant iostreams system of throwing random objects down a stream to change the number formatting pattern. Ugh.
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