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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/CPLUSPLUS/CONCEPT/local_var.html | |
Initial import (2.0.2-6)2.0.2-6
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| -rw-r--r-- | reference/CPLUSPLUS/CONCEPT/local_var.html | 144 |
1 files changed, 144 insertions, 0 deletions
diff --git a/reference/CPLUSPLUS/CONCEPT/local_var.html b/reference/CPLUSPLUS/CONCEPT/local_var.html new file mode 100644 index 0000000..f6cb994 --- /dev/null +++ b/reference/CPLUSPLUS/CONCEPT/local_var.html @@ -0,0 +1,144 @@ +<html> +<head> +<title>C++ Local Variables.</title> +</head> +<body bgcolor="#dddddd"> +<font color=brown> +<hr> +<center><h1>C++ Local Variables.</h1></center> +<hr> +<p> + +There is not much difference between +<a href=../../C/SYNTAX/glo_int_vars.html> C local variables</a> but there +is one important feature that should be noted. +<ul> +<li>Variable definitions are now considered to be executable statements. +</ul> +This means that you can now put variable definitions anywhere in the code +and not jut at the start of a +<a href=../../C/glossary.html#block>block.</a> +Here is an example. + +<p> +<center> +<table bgcolor=ivory width="80%" border=1> +<tr><td> +<pre> + + main() + { + float pi = 3.142; // Usual location for variable definitions + + cout << "PI is " << pi << endl; + + int Count = 1; // C++ allows us to place a definition here. + + while (Count < 10) + { + cout << Count << endl; + } + } +</pre> +</td></tr> +</table> +</center> +<p> + +It should be noted that <b>Count</b> is only in scope (usable) from the +point of definition and to the end of the block. +It can not be used in the previous <b>cout</b> statement. +<p> + +The idea of this feature is to allow you to put variable declarations +near to the place +you wish to use them. Personnaly, I feel this should not be neccasary +if you write small concise functions.... + +There is one natty feature of this facility though. Check this +example out. +<p> +<center> +<table bgcolor=ivory width="80%" border=1> +<tr><td> +<pre> + + main() + { + int Last = 10; + + while (int Count; Count < Last; Count++) + { + cout << Count << endl; + } + } +</pre> +</td></tr> +</table> +</center> +<p> +In this example, <b>Count</b> is defined inside the <b>for</b> +statement and only exists while the for block is being executed. + + +<p> +<hr> +<h2>Examples:</h2> +<!-- +<img src="../../GRAPHICS/computer.gif" alt="o"> +<a href="../EXAMPLES/refvar.cc">Example program.</a> +<p> + +<font color=brown> +<img src="../../GRAPHICS/computer.gif" alt="o"> +<a href="../../C/EXAMPLES/pointer_func.c">Example C program.</a> +</font> +--> + +<hr> +<h2>See Also:</h2> + +</font> +<hr> +<font color=black> +<h2>C References</h2> +<p> + +<img src="../../GRAPHICS/whiteball.gif" alt="o"> +<a href=../../C/SYNTAX/glo_int_vars.html> C local variables</a> +<p> +<img src="../../GRAPHICS/whiteball.gif" alt="o"> +<a href="../../C/CONCEPT/data_types.html">data types</a>. + +</font> + +<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="../../C/master_index.html">Master Index</a> +</td><td width="25%"> +<a href="../SYNTAX/keywords.html">Keywords</a> +</td><td width="25%"> +<a href="../../C/FUNCTIONS/funcref.htm">Functions</a> +</td> +</tr> +</table> +</center> +<p> +<hr> +<font color=brown> +<address>Martin Leslie +<script language="JavaScript"> +<!-- // +document.write(document.lastModified); +// --> +</script> +</address><p> +</font> +</body> +</html> |