05-02-2022, 01:04 AM
Functional Programming (FP) is a method of problem solving like other methods OOP or Procedural. It includes Pure Functions that don’t include side effects in the program. It has a strict control flow meaning that it takes input as argument and returns the output directly. This style of programming is based on functions. The key part of FP is Higher-order Functions. Higher-order Function is that which takes functions as arguments, or returns them as result.
Let’s write the code for better understanding of FP. First let’s try this with the procedural method. So this program adds two numbers and returns the square of them. Let's code it.
Code:
# Imperative way
def squared_sum(x,y):
sum = x + y
square = sum ** 2
return square
print(squared_sum(10,4))This function has side effects because variables used in this case ‘sum’ and 'square’ are affecting something which in this case is memory. Side effects are events caused by the system within limited scope whose effects are felt outside of that scope. Now let’s see the above example in the Functional Programming approach.
Code:
# Functional Programming approach
def squared_sum(x,y):
return (x + y) ** 2
print(squared_sum(10,4))This approach helps the developer to easily understand the operations of a given system.
Now let’s see another example which includes higher-order functions.
Code:
def test(func, arg):
return(func(func(arg)))
def mult(x):
return x*x
print(test(mult,2))
Output: 16focus on this :
return func(func(arg)) == mult(mult(2))
2 is passed to the function mult the result is 4 and now we are passing the result of that function again
Inside/Argument = mult(2) = 4
Outside/Returned = mult(inside) = mult(4)
Hope you get the Logic.
That’s it for today in the next thread we will talk about pure functions in detail.
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Allah Hafiz and Good Bye Till the next post"
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