The First Class Function

A medium Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

medium

Seniority

L4

Problem

Implement two functions: apply_twice(f, x) returns f(f(x)); compose(f, g) returns lambda x: f(g(x)). The test harness calls test cases with 'f', 'g', 'x', 'op' and a registry of named functions ('double' = x*2, 'inc' = x+1). Return the list of results.

Summary

Functions travel as values - prove you can pass one around.

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