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| author | Tobias Klauser <tklauser@distanz.ch> | 2008-01-27 11:37:44 +0100 |
|---|---|---|
| committer | Tobias Klauser <tklauser@xenon.tklauser.home> | 2008-01-27 11:37:44 +0100 |
| commit | 7e0f021a9aec35fd8e6725e87e3313b101d26f5e (patch) | |
| tree | b1cacc4b24393f517aeb4610e9e1021f954307a8 /reference/C/CONCEPT/true_false.html | |
Initial import (2.0.2-6)2.0.2-6
Diffstat (limited to 'reference/C/CONCEPT/true_false.html')
| -rw-r--r-- | reference/C/CONCEPT/true_false.html | 78 |
1 files changed, 78 insertions, 0 deletions
diff --git a/reference/C/CONCEPT/true_false.html b/reference/C/CONCEPT/true_false.html new file mode 100644 index 0000000..db7f90e --- /dev/null +++ b/reference/C/CONCEPT/true_false.html @@ -0,0 +1,78 @@ +<title>True or False</title> +<body bgcolor="#ffffcc"> +<hr> +<center> +<h1>True or False.</h1> +</center> +<hr> +The concept of an <a href="../CONCEPT/expressions.html">expression</a> evaluating to true or false is one of +the corner stones of C. BUT the language derives true and false in an +unusual way.<p> +Basicly there is no boolean value. The number 0 is considered to be false +and all other numbers are considered to be true....<p> + +Please consider the following expressions. + +<pre> + (1 == 1) true + (1 != 1) false + (i = 1) true + (i = 0) false + (i = 1 + 1) true +</pre> +The first two examples should be clear but the last ones need explanation .<p> +The last three examples assign a value to a variable and a side effect of +assignment is to return the value assigned, it is <b>this</b> value that is tested +to be true or false.<p> +Looking at the last example: +<pre> + (i = 1 + 1) + (i = 2) + (2) +</pre> + +<ul> +<li>The third expression assigns a value of 1 to <b>i</b>. 1 is considered to +be true because it is non-zero. +<p> +<li>The fourth expression assigns a value of 0 to <b>i</b>. 0 is considered to +be false. +<p> +<li>The fith expression assigns a value of 2 to <b>i</b>. 2 is considered to +be true, because it is non-zero. +</ul> +<p> +<hr> +<h2>See Also:</h2> +<img src=../../GRAPHICS/whiteball.gif> +<A HREF="../SYNTAX/enum.html">enum keyword</A> +<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="../SYNTAX/keywords.html">Keywords</a> +</td><td width=25%> +<a href="../FUNCTIONS/funcref.htm">Functions</a> +</td> +</tr> +</table> +</center> +<p> + +<hr> +<address>Martin Leslie +<script language="JavaScript"> +<!-- // +document.write(document.lastModified); +// --> +</script> +</address> Corrections made by Christopher Wolf +<! cwolf@tools.micro.ti.com> + + |