diff options
Diffstat (limited to 'reference/C/CONCEPT/inc_dec.html')
| -rw-r--r-- | reference/C/CONCEPT/inc_dec.html | 84 |
1 files changed, 84 insertions, 0 deletions
diff --git a/reference/C/CONCEPT/inc_dec.html b/reference/C/CONCEPT/inc_dec.html new file mode 100644 index 0000000..dd8216b --- /dev/null +++ b/reference/C/CONCEPT/inc_dec.html @@ -0,0 +1,84 @@ +<title>Increment and decrement.</title> +<body bgcolor="#ffffcc"> +<hr> +<center> +<h1>Increment and decrement.</h1> +</center> +<hr> + +The traditional method of incrementing numbers is by coding something like: +<pre> + a = a + 1; +</pre> +Within C, this syntax is valid but you can also use the ++ operator to perform +the same function. +<pre> + a++; +</pre> +will also add 1 to the value of <b>a</b>. +By using a simular syntax you can also decrement a variable as shown below. +<pre> + a--; +</pre> +These operators can be placed as a prefix or post fix as below: +<pre> + a++; ++a; +</pre> +When used on their own (as above) the prefix and postfix have the same effect +BUT within an expression there is a subtle difference....<p> + +<ol> +<li>Prefix notation will increment the variable BEFORE the +expression is evaluated. +<li>Postfix notation will increment AFTER the expression evaluation. +</ol> + +Here is an example: +<pre> + main() main() + { { + int a=1; int a=1; + printf(" a is %d", ++a); printf(" a is %d", a++); + } } + +</pre> + +In both examples, the final value of <b>a</b> will be 2. BUT the first +example will print 2 and the second will print 1. + +<hr> +<img src=../../GRAPHICS/computer.gif> +<a href="../EXAMPLES/inc_dec.c"> Example program.</a><br> + +<img src=../../GRAPHICS/whiteball.gif> +<a href="../CONCEPT/expressions.html">Other operators.</a><br> + +<img src=../../GRAPHICS/whiteball.gif> +<a href="../CONCEPT/precedence.html">Operator precedence table.</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> |