Difference between Function and Method

Function vs Method

In the language of programming, two common names will be used over and over. These are ‘function’ and ‘method’.  In simple terms, the use of ‘function’ relates to a program component that is required to perform a specific task that it ‘knows’ how to perform.  The function takes up an input, does some internal calculations to the input, and then provides a final result, with a change to the naming properties.  The main benefit of using a function in programming is that it can be repetitively used to perform different tasks, and does not need reprogramming, as they are expected to return a value.

‘Methods’, on the other hand, are blocks of code which are created to contain a series of statements. These statements will be executed following a program initiating any of the arguments defined in the methods. Below are the differences that have been observed between these two common programming statements. One of the biggest differences between the two is that ‘method’ is only used in cases dealing with object oriented programming language such as Java, C++ and C#.

The use of method is manifested as an object associated with or bound to the same class that the method is in. Function on the other hand applies both to languages that are not object oriented, like C, and languages that are object oriented. The assessment of functions can occur at any point and it is not only limited to the static functions.  This is quite different to the access levels that are used in methods which are set to public, private or even protected. Functions also have interdependent existences and for this reason, it is not uncommon to find the presence of functions outside the class; a good example of this is the class Ex:main() function that is seen in C++ and C languages. Methods, on the other hand, don’t have an interdependent existence and have to be defined within the class Ex:-main () which is a method in C#.

The definition of functions occurs through structured languages such as Pascal and C, as well as object oriented language such as JavaScript. Methods on the other hand are only defined in object oriented languages like Java and C#. Functions are independently called, while methods have to use an object or an instance to call them. Methods as units of code manipulate the instance variable of a given class, which differs with the way functions deal with their code, in that functions are a self-describing unit of code.

When operating with functions, no reference variables are employed. This differs significantly when using methods, which have to be called by their reference variables. All data passing through a function are explicitly passed, while data passing through a method are implicitly passed.

Summary

‘Function’ is a segment of code that executes an action and gives out a reply.

‘Method’ is a segment occurring as a series of statements and is executed upon initiation of arguments in the method.

The existence of functions is independent, while methods do not have an independent existence.

The definition of a function occurs in languages such as Pascal, JavaScript, and C, while a method is defined in object-oriented languages, with the most common being Java and C#.

Functions are called independently while an instance or object is used to call methods.

The functions are a self-describing unit of code, while methods can be used to manipulate an instance variable of a given class which is of interest.