Python Coding challenge - Day 501| What is the output of the following Python Code?

 

Code Explanation:

Line 1: Define combine function

def combine(f, g):

    return lambda x: f(g(x))

Explanation:

This function takes two functions f and g as inputs.

It returns a new anonymous function (lambda) that takes an input x, applies g(x) first, and then applies f() to the result of g(x).

In other words, it returns f(g(x)) — this is called function composition.

Line 2: Define f

f = lambda x: x ** 2

Explanation:

f is a lambda function that squares its input.

Example: f(4) = 4 ** 2 = 16

Line 3: Define g

g = lambda x: x + 2

Explanation:

g is a lambda function that adds 2 to its input.

Example: g(3) = 3 + 2 = 5

Line 4: Compose functions using combine

h = combine(f, g)

Explanation:

h is now a new function created by combining f and g.

h(x) will compute f(g(x)), which is:

First: g(x) → add 2

Then: f(g(x)) → square the result

Line 5: Call and print h(3)

print(h(3))

Step-by-step Evaluation:

h(3) = f(g(3))

g(3) = 3 + 2 = 5

f(5) = 5 ** 2 = 25

So, h(3) = 25

Final Output:

25