When two or more methods in the same class have the same name but different parameters?
This chapter reviews method parameters and local variables, as well as method overloading and method signature. Method overloading means two or more methods have the same name but have different parameter lists: either a different number of parameters or different types of parameters. When a method is called, the corresponding method is invoked by matching
the arguments in the call to the parameter lists of the methods. The name together with the number and types of a method's parameter list is called the signature of a method. The return type itself is not part of the signature of a method. Colors in the following show how this works. public Mystery( int sum ) public void increment( int inc ) public class Tester Now look at this modified version: class Mystery 1.14. Defining Two or More Methods with the Same NameProblemYou would like to implement two or more methods with the same name in one object. In object-oriented programming, this is called method overloading. However, in Objective-C, method overloading does not exist in the same way as it does in other programming languages such as C++. SolutionUse the same name for your method, but keep the number and/or the names of your parameters different in every method:
This example shows a typical pattern in overloading. Each rectangle can be drawn either filled (solid color) or empty (showing just its boundaries). The first procedure is a “convenience procedure” that allows the caller to avoid specifying how to fill the rectangle. In our implementation of the first procedure, we merely call the second procedure, making the choice for the caller (
DiscussionYou can define two methods with the same name so long as they differ in the parameters they accept. One reasons for doing this is one function offers more customization (through parameterization) than the other function. Method overloading is a programming language feature supported by Objective-C, C++, Java, and a few other languages. Using this feature, programmers can create different methods with the same name, in the same object. However, method overloading in Objective-C differs from that which can be used in C++. For instance, in C++, to overload a method, the programmer needs to assign a different number of parameters to the same method and/or change a parameter’s data type. In Objective-C, however, you simply change the name of at least one parameter. Changing the type of parameters will not work:
Changing the return value of these methods will not work either:
As a result, you need to change the number of parameters or the name of (at least) one parameter that each method accepts. Here is an example where we have changed the number of parameters:
Here is an example of changing the name of a parameter:
Can you spot the difference between the declarations of
these two methods? The first method’s second parameter is called Here is another example of two methods that draw a circle but have different names for their second parameter:
Here is a concise extract of the things to look out for when constructing and working with methods:
When two or more methods in the same class have the same name but different parameter lists?Method overloading means two or more methods have the same name but have different parameter lists: either a different number of parameters or different types of parameters.
Can a class have two methods with the same name but different in parameters called?If a class has multiple methods having same name but parameters of the method should be different is known as Method Overloading.
When two methods in the same class have the same name but different arguments This is an example of?Two or more methods can have the same name inside the same class if they accept different arguments. This feature is known as method overloading.
When there are multiple functions with same name but different parameters are called?Function overloading is a feature of object-oriented programming where two or more functions can have the same name but different parameters.
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