What is Pure Function | Functional Programming in Scala

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What is Functional Programming?

Firstly, Functional programming is a programming paradigm in which everything is bound using pure mathematical functions. It’s a declarative programming approach. In contrast to an imperative style, which focuses on “how to solve,” it focuses on “what to solve.” Instead of statements, it uses expressions. A statement is executed to assign variables, but an expression is evaluated to create a value. In addition, Those functions have some unique characteristics.

Components of functional programming

Pure functions
Recursion
Referential transparency
Functions are First-Class and can be Higher-Order
Immutability

What is a Pure Function?

Pure functions are normal functions with some characteristics :

Total / Not Partial
No Randomness
No Side Effects
Not Null
No Exception
No Mutation

Example of Pure Function

def add(a: Int, b: Int): Int = a + b

Example of Not a Pure Function

def divide(a: Int, b: Int): Int = a / b

The ‘divide’ function passes all the parameters of being a pure function but if in case ‘a’ will be divided by 0, Then it will throw an exception which will make it not a pure function.

Advantages and disadvantages of Functional Programming

Advantages:

This programming aids in the effective resolution of difficulties.
It improves modularity.
It allows us to implement lambda calculus in order to solve complex problems
Some programming languages support nested functions so it improves the maintainability of the code
It reduces complex problems into simple pieces so that it will be easy to solve.

Disadvantages:

It’s difficult to grasp for novices, hence it’s not a beginner-friendly paradigm approach for new programmers.
Maintenance is difficult during the coding phase when the project size is large
Moreover, Reusability in Functional programming is a tricky task for developers

For further information on functional programming wait for the next blog…