Function vs Method: Difference and Comparison

In the era of technology and computer, programming language plays an important role. Programming language is the way through which we can communicate with software on a computer. A computer only understands Machine level language. The base of programming language is function and method.

Key Takeaways

  1. A function is a block of code that performs a specific task, whereas a method is a function associated with an object or a class.
  2. Functions return a value by default, whereas a method can return a value or not, depending on its implementation.
  3. Functions are not associated with a specific object or class, whereas methods are always associated with an object or a class.

Function vs Method

The difference between function and method is that function is free of any object, whereas method itself is static or is on an object. The C language has no methods, it has only functions, whereas C++ and JAVA have no functions, they only have methods. The object-oriented word for a method is function.

Function vs Method

A function is a piece of code with a name that can pass and optionally return data to operate on. In other words, the work of function in any programming language is to give a result in return for the data(parameters) given. A function can be used multiple times. The function can also be called upon from inside of any other function too.

While the method is known as an OOP (object-oriented programming language) because an object comprises data and behavior, and this comprises an interface. This is how it can be determined whether an object can be utilized or not. For example – a “window” is an object which consists of methods “open” and “close” having some data and behavior.

Comparison Table

Parameters of ComparisonFunctionMethod
Basis of dataOnly works with the provided data. It can access all the data linked with the class.
Data PrivacyFunction cannot operate or access private data, if any. Method can operate with the private data of the class, if any.
TypeFunctions can describe its own code. Methods are Object-oriented programming language.
Languages C language has functions and no methods. JAVA and C++ languages have methods but no function.
ClassDeclaration of class is not needed.Methods are coded inside a class.

What is Function?

Functions are a group of instructions that are bundled together to attain a specific outcome. A function can increase the reusability of a particular code. Any values can be passed on using variables to a function. Variables are categorized into two – arguments and parameters.

In JAVA, we start the programming with a class followed by the next line stating “public static void main ()” the ‘public’ denotes an access specifier and is used to manage which part of the content should be accessible.

There are certain rules to be followed for defining a function in programming languages like JAVA and C++. For example, in JAVA, the rules for defining a Function are that multiple functions having the same signature cannot be declared, i.e., having the same parameters and numbers cannot be repeated. An example of a function in JAVA is given below for reference, Int findMinimum (int num1, int num2, int num3) { If (num1 > num2) return num1; { elseif (num3 > num1) return num3; else return num1; } } In C programming language, functions are of two types, predefined and user-defined functions.

Functions like puts(), gets(), printf(), scanf(), etc are predefined library functions. For example, – printf() function is described in <stdio.h> header file therefore, to use the printf() function, the <stdio.h> header file must be included in the program using #include <stdio.h>.

The functions that are created by the user in a program are known as user-defined functions. The syntax of the user-defined function is; return_type function_name (argument list) { Set of statements – Block of code }. The return type can be data such as char, int, void, etc. The argument list is for comparing two return-type data. The block of code is a group of C language programming statements that will be executed whenever a call is made to the function during the execution.

What is Method?

Methods are defined as Object-oriented programming languages. Methods are also classified into three types: interface method, constructor method, and implementation method.

In programming, a method is written as; String getMyName() { return “Davina Claire”; } In this above example of a method, getMyName() is the method signature. { return “Davina Claire”; } is the Method Body. A string is the return type, and return “Davina Claire”; is the return statement.

To add methods inside a class, add the method hello() to the class; class Car { public $comp; public $color = ‘black’; public $hasSunRoof = true; public function hello() { return “beep”; } } Result: – Beep, Beep.

The full program will be; <?php // Declare the class class Car { // properties public $comp; public $color = ‘black’; public $hasSunRoof = true; // method that says hello public function hello() { return “beep”; } } // Create an instance $alto = new Car (); $swiftDzire = new Car (); // Get the values echo $alto -> color; // black echo “<br />”; echo $swiftDzire -> color; // black echo “<hr />”; // Set the values $alto -> color = ‘red’; $alto -> comp = “ALTO”; $swiftDzire -> comp = “SWIFTDZIRE”; // Get the values again echo $alto -> color; // red echo “<br />”; echo $swiftDzire -> color; // black echo “<br />”; echo $alto -> comp; // ALTO echo “<br />”; echo $swiftDzire -> comp; // SWIFTDZIRE echo “<hr />”; // Use the methods to get a beep echo $alto -> hello(); // beep echo “<br />”; echo $swiftDzire -> hello(); // beep

Main Difference Between Function and Method

  1. A function is directly called by its name, whereas a method includes a code that is called by the object’s name.
  2. A function can pass and then return the data that is operated, whereas a method operates data in a Class.
  3. A function is independent, whereas a method is a function linked with an object.
  4. Explicit data is passed on to a function, whereas a method completely passes the object on which it was called in the program.
  5. A method is Object-oriented programming, while a function has standalone functionality.
References
  1. https://www.sciencedirect.com/science/article/pii/S0096300309010376
  2. https://www.sciencedirect.com/science/article/pii/S0960077905004054

Last Updated : 11 June, 2023

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15 thoughts on “Function vs Method: Difference and Comparison”

  1. This article is enlightening. The explanation of the rules for defining functions in Java and C++ helps clarify the nuances of programming languages.

    Reply
  2. The article does an excellent job of explaining the roles and characteristics of functions and methods. The example codes provide a clear understanding of their implementation.

    Reply
  3. The article provides a comprehensive overview of the concepts. The comparison between Java and C++ for defining functions gives a clear understanding of their syntax and rules.

    Reply
    • Absolutely, I found the information about defining functions in different programming languages extremely valuable. It allows us to see how languages differ in their approach to functions and methods.

      Reply
  4. The distinction between functions and methods is clearly outlined. The comparison table effectively summarizes the differences, making it easier to grasp.

    Reply
  5. The detailed explanation of how functions and methods operate in different programming languages gives a holistic understanding of their significance.

    Reply
    • I found the example of a function in JAVA very informative and relevant. The article effectively communicates the essence of functions and methods.

      Reply
  6. The in-depth comparison between functions and methods in various programming languages is an excellent demonstration of their roles in software development.

    Reply
  7. The article effectively describes the fundamental differences between functions and methods. The clear comparison table highlights the importance of both in computer programming.

    Reply
    • I agree, the detailed explanation helps to understand the roles of functions and methods in different programming languages.

      Reply
    • Yes, I found it informative as well. The example codes are a great way to illustrate how functions and methods are implemented in different programming languages.

      Reply
  8. This article is a great resource for understanding functions and methods in computer programming. The examples provided in different languages are especially valuable.

    Reply

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