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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/CPLUSPLUS/CONCEPT/funcoverload.html | |
Initial import (2.0.2-6)2.0.2-6
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| -rw-r--r-- | reference/CPLUSPLUS/CONCEPT/funcoverload.html | 153 |
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diff --git a/reference/CPLUSPLUS/CONCEPT/funcoverload.html b/reference/CPLUSPLUS/CONCEPT/funcoverload.html new file mode 100644 index 0000000..a245e32 --- /dev/null +++ b/reference/CPLUSPLUS/CONCEPT/funcoverload.html @@ -0,0 +1,153 @@ +<html> +<head> +<title>Function Overloading.</title> +</head> +<body bgcolor="#dddddd"> +<font color=brown> +<hr> +<center><h1>Function Overloading.</h1></center> +<hr> +<p> +Overloading is a technique that allows you to give a several +functions with the same name but different parameter lists. +<p> +Consider the following program. +<p> +<center> +<table border=1 width="80%" bgcolor="ivory"> +<tr> +<td> +<pre> + + #include <iostream.h> + + void Add(int Left, int Right); + + main () + { + Add(5, 9); // Integer Add. + Add(3.2, 7.1); // Floating point Add. + } + + // Integer version of Add. + + void Add(int Left, int Right) + { + cout << Left << " + " << Right << " = " << Left+Right << endl; + } +</pre> +</td> +</tr> +</table> +</center> +<p> +The program contains the <b>Add</b> function that adds integers. +But the main calls it twice, once passing integers and the second +time passing floating point numbers. The program will compile and run +but you will get incorrect results because the floats will be +<a href=../../C/CONCEPT/cast.html> cast</a> to integers. +<p> +The second +program offers a solution by <b>overloading</b> the <b>Add</b> function. + +<p> +<center> +<table border=1 width="80%" bgcolor="ivory"> +<tr> +<td> +<pre> + + #include <iostream.h> + + void Add(int Left, int Right); + <b>void Add(double Left, double Right);</b> + + main () + { + Add(5, 9); // Integer Add. + Add(3.2, 7.1); // Floating point Add. + } + + // Integer version of Add. + + void Add(int Left, int Right) + { + cout << Left << " + " << Right << " = " << Left+Right << endl; + } + <b> + // float version of Add. + + void Add(double Left, double Right) + { + cout << Left << " + " << Right << " = " << Left+Right << endl; + } +</b> +</pre> +</td> +</tr> +</table> +</center> + +The compiler can now look at the call list and match it with +a function with the correct parameter list and the floating +point addition is performed correctly. + +<p> + +Please note that the returned argument is not used when matching +overloaded functions. + + +<hr> +<h2>Examples:</h2> +<img src="../../GRAPHICS/computer.gif" alt="o"> +<a href="../EXAMPLES/overload.cc">Example program.</a> +<p> + +<hr> +<h2>See Also:</h2> + +<img src="../../GRAPHICS/whiteball.gif" alt="o"> +<a href="fundefault.html">Default Parameter Values.</a>. + + +</font> +<hr> +<font color=black> +<h2>C References</h2> +<p> +<img src="../../GRAPHICS/whiteball.gif" alt="o"> +<a href="../../C/SYNTAX/functions.html">Function Basics</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> |