Overloading dan Overriding Kotlin

RIKI AFRIANSYAH

11 Nov 202216:23

Summary

TLDRThis video discusses the key differences between method overloading and method overriding in object-oriented programming. Method overloading occurs when a class has multiple methods with the same name but different parameters, allowing flexibility in input types. In contrast, method overriding involves a subclass using the same method name as its parent class, but altering its behavior. The video explains these concepts with practical code examples, showcasing how method signatures and inheritance affect functionality. It also hints at future discussions on access modifiers, like private and protected, to deepen understanding.

Takeaways

📚 Overloading allows methods with the same name in a class to have different parameters (e.g., different data types or number of parameters).
🔢 Overloading works by differentiating methods based on the number and type of input parameters, even if they share the same name.
🔄 Overriding occurs when a subclass has a method with the same name and parameters as its parent class, but it provides its own implementation.
📏 The script explains overloading using a 'Rectangle' class example, where multiple 'calculate' methods take different parameter types (integer vs. double).
💡 Overloading is flexible, allowing methods with the same name but different input types or parameter counts, as long as they don't create ambiguity.
🚫 Two methods cannot have the same name and the same number/type of parameters in the same class because it would cause a conflict.
🧱 The script illustrates overriding using a 'Block' class that inherits from the 'Rectangle' class, where the child class redefines a 'display' method.
⚙️ The 'super' keyword is used to call the parent class's constructor in the child class when overriding.
🔍 When overriding, if a method exists in both the parent and child classes, the child class's version will be called unless specified otherwise.
🔑 The script also mentions that access modifiers like 'open', 'private', and 'protected' affect method visibility, which will be explained later.

Q & A

What is method overloading?
-Method overloading is a feature in object-oriented programming where a class has multiple methods with the same name but different parameters (different number, type, or order of parameters). The method to be executed is determined by the argument list during the call.
What is method overriding?
-Method overriding occurs when a subclass provides a specific implementation for a method that is already defined in its parent class. The method in the child class must have the same name, return type, and parameters as the method in the parent class.
What is the main difference between method overloading and method overriding?
-The main difference is that overloading happens within a single class and deals with multiple methods having the same name but different parameters. Overriding, on the other hand, involves a child class redefining a method that is already defined in its parent class, keeping the same name and parameters.
Can method overloading have different return types?
-Yes, method overloading can have different return types, as long as the parameter lists are different. However, the return type alone cannot be used to distinguish overloaded methods.
In the provided script, how does the `hitung` method demonstrate method overloading?
-The `hitung` method in the `PersegiPanjang` class is overloaded by creating multiple methods with the same name (`hitung`) but different parameter types (e.g., `int` vs. `double`) and different numbers of parameters.
How does the `display` method demonstrate method overriding in the script?
-The `display` method is defined in both the parent class (`PersegiPanjang`) and the child class (`Balok`). The method in the child class overrides the parent class method to provide a more specific implementation that includes additional attributes (e.g., height).
What happens if two overloaded methods have the same number and type of parameters?
-If two overloaded methods have the same number and type of parameters, the compiler will not be able to differentiate between them, causing an error. Overloaded methods must differ either in the number, order, or type of parameters.
Why is the `override` keyword used in method overriding?
-The `override` keyword explicitly indicates that a method is meant to override a method from its parent class. This helps in ensuring that the method signature matches the parent's method, reducing the risk of errors.
What is the purpose of the `super` keyword in the script?
-The `super` keyword is used to call the constructor of the parent class from the child class (`Balok`). This ensures that the parent class attributes (length and width) are initialized before additional attributes are set in the child class.
How does the script illustrate the difference between method overriding and method overloading?
-The script uses the `hitung` method to illustrate overloading by defining multiple `hitung` methods with different parameters within a single class. It demonstrates overriding by defining the `display` method in both the `PersegiPanjang` and `Balok` classes, showing how the child class method takes precedence when called from a child class instance.

Outlines

00:00

📚 Understanding Overloading

This paragraph explains the concept of method overloading in programming. Overloading occurs when a class has multiple methods with the same name but different parameters. The key difference between the methods is the number or type of parameters they accept. An example is given with a 'persegi panjang' (rectangle) class that has two 'hitung' (calculate) methods: one with integer parameters for length and width, and another with double parameters for the same. This allows the class to handle different data types and numbers of arguments without confusion.

05:00

🔄 Overloading with Different Parameters

The paragraph delves deeper into method overloading by illustrating how a method can be called with different parameter types or counts without causing errors. It uses the example of a 'hitung' method that can accept two parameters of the same type (integer or double) or three parameters (integer) to calculate volume. The explanation clarifies that overloading is about having the same method name with varying parameters, which can include different data types or a different number of parameters.

10:01

🔄 Overriding Methods in Inheritance

This section introduces method overriding, which is different from overloading. Overriding occurs when a subclass has a method with the same name as a method in its superclass. The example provided involves a 'balok' (cube) class inheriting from a 'persegi panjang' (rectangle) class. The 'balok' class has its own 'display' method, which is an override of the 'display' method in the superclass. The paragraph explains how the overridden method in the subclass is called instead of the one in the superclass when an object of the subclass is used.

15:04

🔄 Clarifying Overloading and Overriding

The final paragraph summarizes the differences between overloading and overriding. Overloading is about having methods with the same name but different parameters in the same class, while overriding is about a subclass having a method with the same name as a method in its superclass. The paragraph emphasizes the importance of understanding these concepts for proper class design and method implementation in object-oriented programming.

Mindmap

Keywords

💡Overloading

Overloading refers to a concept in object-oriented programming where multiple methods within the same class share the same name but differ in the parameters they take (e.g., type, number of parameters). In the script, the speaker illustrates overloading with the example of methods that calculate area but differ in the parameter types, such as using integers versus doubles.

💡Overriding

Overriding is when a subclass or child class provides a specific implementation of a method that is already defined in its parent class. The method in the subclass has the same name and parameters as in the parent class. In the video, overriding is shown through a 'display' method in both the 'balok' and 'persegi panjang' classes, where the subclass 'balok' overrides the parent class’s method.

💡Method

A method is a function defined within a class that performs a specific task. Methods can take parameters and return values. The script frequently discusses methods in terms of their role in both overloading and overriding, such as the 'hitung' method that calculates area, but with different parameter types.

💡Class

A class in object-oriented programming is a blueprint for creating objects, defining their attributes and behaviors through variables and methods. In the script, examples include 'persegi panjang' (rectangle) and 'balok' (cuboid) as classes that define methods like 'hitung' and 'display'.

💡Parameter

A parameter is a variable used in a method to accept input values. Parameters define how the method functions based on the input provided. In the script, parameters such as 'panjang' (length), 'lebar' (width), and 'tinggi' (height) are passed to the 'hitung' method to calculate area and volume, highlighting the role of different types of parameters in overloading.

💡Return type

The return type of a method specifies the type of value it will return after execution. For example, in the script, different return types like 'integer' and 'double' are shown in overloaded 'hitung' methods. The method returns the result of multiplying length and width, with the return type varying based on input types.

💡Superclass

A superclass is a parent class from which other classes (subclasses) inherit methods and attributes. In the script, 'persegi panjang' is a superclass, and 'balok' is its subclass, which inherits and overrides methods from 'persegi panjang', demonstrating the relationship between superclass and subclass.

💡Subclass

A subclass is a class that inherits from a superclass and can override or extend its behavior. The script describes 'balok' as a subclass of 'persegi panjang', overriding the 'display' method to include additional behavior like displaying the height, alongside the length and width.

💡Constructor

A constructor is a special method in a class used to initialize objects. It assigns initial values to the attributes of the object. The script mentions constructors in both 'persegi panjang' and 'balok' classes, where attributes like 'panjang' (length), 'lebar' (width), and 'tinggi' (height) are set when an object is created.

💡Access modifier

An access modifier defines the scope and visibility of a class, method, or variable. Examples include 'public', 'private', and 'protected'. The script mentions that understanding access modifiers like 'Open' will be important later, indicating the control of how methods or properties are accessed in different contexts.

Highlights

Overloading refers to having methods with the same name within a class but with different parameters, such as type or number of parameters.

In overloading, as long as method signatures differ, the methods can coexist within the same class without confusion.

Overloading is illustrated with a class that calculates the area of a rectangle using methods with different parameter types (e.g., integer vs double).

Overloading can also differ by the number of parameters, such as adding a third parameter to the method for height.

Methods in overloading can vary by the number of parameters or their data types but cannot have identical parameter signatures.

Override refers to redefining a method in a child class that already exists in the parent class with the same signature.

Overriding allows the child class to have its own specific implementation of a method that shares the same name and parameters as the parent class.

When a method is overridden in the child class, calling it from the child object will execute the child class's version of the method.

To override a method, the method signature (name and parameters) must be identical in both the parent and child classes.

If the parent class method needs to be called within the overridden method, the `super` keyword is used to access the parent class's implementation.

Overloading is restricted to methods in the same class, while overriding deals with methods across parent and child classes.

Overloading provides flexibility by allowing methods with the same name to process different data types or parameter counts.

Overriding supports polymorphism, allowing different implementations of the same method to behave differently in child classes.

The use of the `open` keyword allows methods in Kotlin to be overridden, ensuring access for overriding in child classes.

The main difference between overloading and overriding is that overloading involves methods in the same class, while overriding involves methods across a class hierarchy.