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<title>printf function</title>
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<h1>printf function</h1>
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<p>
<b>printf</b> is used to O/P data to
<a href="../MISC/stdfiles.html">STDOUT</a> (usually the screen). It has many
formatting options which we shall look at in a moment.
<hr>
<h2>printf syntax</h2>
This is an example of <b>printf</b> in its simplest form.
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#include <stdio.h>
main()
{
printf("This text will appear on the screen\n");
}
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<p>
printf is passed one formatting argument.
The unusual thing about the example (in my mind) is <b>\n</b>, this is actually
an <a href="escape.html"> escape sequence</a> that signals a new line. Without
it, any printf's
that follow would O/P to the same line.
<b>printf</b> also takes extra arguments which are inserted into the format
string at locations marked with a <b>%</b>.
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<pre>
#include <stdio.h>
main()
{
int number=42;
printf("The answer is %i\n", number);
}
</pre>
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<p>
What happens here is the <b>%i</b> is seen as a
<a href="format.html">formatting identifer</a> for the
next argument (number). In this case an integer is expected.<p>
<hr>
<h2>See also</h2>
<ol>
<li><a href="puts.html">puts</a> Much easier to use - but not as powerfull.
<li><a href="sprintf.html">sprintf</a> Same as 'printf' but O/P to a string array.
<li><a href="../CONCEPT/string.html">Strings</a>.
<li><a href="../SYNTAX/idioms.html#printf">A dead handy printf idiom.</a>.
</ol>
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<hr>
<address>Martin Leslie
</address><p>
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