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<!--
~ Author: @tridib2003
~ Repository: https:/tridib2003/levelupjava
-->
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Overloading & Overriding | Level-Up Java</title>
<link href="styles.css" rel="stylesheet">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
</head>
<body>
<nav class="navigation-std">
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<li class="ul-inline-item nav-pills-decor">
<a class="link" href="/">Previous</a>
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</nav>
<h1 class="h1-basic">Method Overloading</h1>
<div class="desc-container desc-container-center desc-std">
<hr>
<ul>
<li>
<p>
<strong>Method overloading</strong> is the process of having two or more methods within the same
class having the same name but different parameter declarations.
</p>
</li>
<li>
<p>
When an overloaded method is invoked, Java uses the type and/or number of arguments to determine
which version of the overloaded methods to execute,
which essentially means that the overloaded methods must differ in their type and/or the number of
their parameters.
</p>
</li>
<li>
<p>
The return type of overloaded methods alone is insufficient to distinguish between multiple versions
of the methods,
thus Java matches the parameters of the overloaded methods with the arguments being passed during
method invocation to resolve the ambiguity.
</p>
</li>
<li>
<p>
When methods are overloaded each version of the method can perform any activity it is designed to
do,
but as a good practice a set of overloaded methods must be designed to perform a task which has the
same underlying logic.
</p>
</li>
</ul>
</div>
<br><br><br>
<div class="table-container table-container-center">
<table class="table-code-links">
<tr>
<td>
Demonstrate <strong>Method Overloading</strong>
</td>
<td>
<div class="btn-container-center">
<a class="btn-link btn-link-color1"
href="https:/tridib2003/levelupjava-wiki/blob/main/Overloading-%26-Overriding/MethodOverloadingDemo.java"
target="_blank">
<i class="fa fa-github" style="font-size: 18px; color: whitesmoke;">
<p style="display: inline; margin-left: 0.4rem;">
View code
</p>
</i>
</a>
</div>
</td>
</tr>
</table>
</div>
<h3 class="end-section">. . .</h3>
<h1 class="h1-basic">Constructor Overloading</h1>
<div class="desc-container desc-container-center desc-std">
<hr>
<ul>
<li>
<p>
<strong>Constructor</strong> can also be overloaded in the same way as methods.
</p>
</li>
<li>
<p>
We can have multiple versions of a constructor, differing in the number of parameters.
</p>
</li>
<li>
<p>
When an object is created that version of the constructor is called whose parameters match with the
arguments being passed when it is called.
</p>
</li>
</ul>
</div>
<br><br><br>
<div class="table-container table-container-center">
<table class="table-code-links">
<tr>
<td>
Demonstrate <strong>Constructor Overloading</strong>
</td>
<td>
<div class="btn-container-center">
<a class="btn-link btn-link-color1"
href="https:/tridib2003/levelupjava-wiki/blob/main/Overloading-%26-Overriding/ConstructorOverloadingDemo.java"
target="_blank">
<i class="fa fa-github" style="font-size: 18px; color: whitesmoke;">
<p style="display: inline; margin-left: 0.4rem;">
View code
</p>
</i>
</a>
</div>
</td>
</tr>
</table>
</div>
<h3 class="end-section">. . .</h3>
<h1 class="h1-basic">Method Overriding</h1>
<div class="desc-container desc-container-center desc-std">
<hr>
<ul>
<li>
<p>
A <strong>method</strong> in a subclass is said to <strong>override</strong> a method in its
superclass, if the name and type signature of both the methods are identical.
</p>
</li>
<li>
<p>
When an overridden method is called from within its subclass, the version of the method present in
the subclass will be executed. Thus the method defined by the superclass will be hidden.
</p>
</li>
<li>
<p>
A general class defines a method common to all of its subclasses, while the subclasses inherit the
general properties from their superclass as well as add their own specialized attributes and
methods, thus achieving the <i>one interface, multiple methods</i> aspect of polymorphism. As we
move down the hierarchy from superclass to subclass we are basically moving from lesser to more
specialized classes.
</p>
</li>
<li>
<p>
<strong>Dynamic Method Dispatch</strong> is the way Java implements run time polymorphism. When a
method is overridden, which method to call is resolved during run time, rather than compile time. As
a super class reference variable can refer to a sub class object. It is the type of object being
referred to that determines which version of the overridden method will be executed.
</p>
</li>
</ul>
</div>
<br><br><br>
<div class="table-container table-container-center">
<table class="table-code-links">
<tr>
<td>
Demonstrating <strong>Method Overriding</strong>
</td>
<td>
<div class="btn-container-center">
<a class="btn-link btn-link-color1"
href="https:/tridib2003/levelupjava-wiki/blob/main/Overloading-%26-Overriding/MethodOverridingDemo.java"
target="_blank">
<i class="fa fa-github" style="font-size: 18px; color: whitesmoke;">
<p style="display: inline; margin-left: 0.4rem;">
View code
</p>
</i>
</a>
</div>
</td>
</tr>
<tr>
<td>
Accessing overridden superclass method using <strong>super</strong>
</td>
<td>
<div class="btn-container-center">
<a class="btn-link btn-link-color1"
href="https:/tridib2003/levelupjava-wiki/blob/main/Overloading-%26-Overriding/MethodOverridingDemo2.java"
target="_blank">
<i class="fa fa-github" style="font-size: 18px; color: whitesmoke;">
<p style="display: inline; margin-left: 0.4rem;">
View code
</p>
</i>
</a>
</div>
</td>
</tr>
<tr>
<td>
Demonstrating <strong>Dynamic Method Dispatch</strong>
</td>
<td>
<div class="btn-container-center">
<a class="btn-link btn-link-color1"
href="https:/tridib2003/levelupjava-wiki/blob/main/Overloading-%26-Overriding/DyamicMethodDispatch.java"
target="_blank">
<i class="fa fa-github" style="font-size: 18px; color: whitesmoke;">
<p style="display: inline; margin-left: 0.4rem;">
View code
</p>
</i>
</a>
</div>
</td>
</tr>
</table>
</div>
<br><br><br>
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