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| author | Tobias Klauser <tklauser@distanz.ch> | 2008-01-27 11:37:44 +0100 |
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| committer | Tobias Klauser <tklauser@xenon.tklauser.home> | 2008-01-27 11:37:44 +0100 |
| commit | 7e0f021a9aec35fd8e6725e87e3313b101d26f5e (patch) | |
| tree | b1cacc4b24393f517aeb4610e9e1021f954307a8 /reference/C/SYNTAX/conditional.html | |
Initial import (2.0.2-6)2.0.2-6
Diffstat (limited to 'reference/C/SYNTAX/conditional.html')
| -rw-r--r-- | reference/C/SYNTAX/conditional.html | 120 |
1 files changed, 120 insertions, 0 deletions
diff --git a/reference/C/SYNTAX/conditional.html b/reference/C/SYNTAX/conditional.html new file mode 100644 index 0000000..45b39af --- /dev/null +++ b/reference/C/SYNTAX/conditional.html @@ -0,0 +1,120 @@ +<title>Conditional Expressions</title> + +<head> +<script language="JavaScript"> +</script> +</head> + +<body bgcolor="#ffffcc"> +<hr> +<center> +<h1>Conditional Expressions.</h1> +</center> +<hr> +<p> + + +We have a short-hand construct for some <b>if ... else ...</b> constructs.<p> +Consider the following two examples. +<p> +<center> +<table border=2 bgcolor=ivory> +<th>Example 1</th> +<th>Example 2</th> +<tr> +<td> +<pre> + + if ( x == 1 ) + y = 10; + else + y = 20; + +</pre> +</td> +<td> +<pre> + + y = (x == 1) ? 10 : 20; + +</pre> +</td> +</tr> +</table> +</center> +<p> +These examples both perform the same function. If x is 1 then y becomes 10 +else y becomes 20. The example on the right evaluates the first expression +'(x ==1 )' and if <b>true</b> evaluates the second '10'. If <b>false</b> the +third is evaluated. Here is another example. +<p> +<center> +<table border=2 bgcolor=ivory> +<th>Example 1</th> +<th>Example 2</th> +<tr> +<td> +<pre> + + if ( x == 1 ) + puts("take car"); + else + puts("take bike"); +</pre> +</td> +<td> +<pre> + + (x == 1) ? puts("take car") : puts("take bike"); + + or + + puts( (x == 1) ? "take car" : "take bike"); +</pre> +</td> +</tr> +</table> +</center> +<p> +It has been said that the compiler can create more efficent code from +a <b>conditional expression</b> possibly at the expence of readable code. +Unless you are writing time critical code (and lets face it, thats unlikely) +the more efficent code is not much of a reason to use this construct. +I feel that it has its uses, but should not be lost into some complex +statement, +but, since when did C programmers worry if anyone else could read their +code ;-) +<p> +<hr> +<h2>See also:</h2> +<ul> +<li><a href="if.html">if</a> keyword. +<li><a href="switch.html">switch</a> keyword. +<li><a href="idioms.html#printf">A use within printf.</a>. +</ul> + +<p> + +<hr> +<p> +<center> +<table border=2 width="80%" bgcolor="ivory"> +<tr align=center> +<td width="25%"> +<a href="../cref.html"> Top</a> +</td><td width="25%"> +<a href="../master_index.html"> Master Index</a> +</td><td width="25%"> +<a href="keywords.html"> Keywords</a> +</td><td width="25%"> +<a href="../FUNCTIONS/funcref.htm"> Functions</a> +</td> +</tr> +</table> +</center> +<p> +<hr> +<address>Martin Leslie +</address><p> +</body> +</html> |