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Challenge 2: Error Messages Using Maybe Monad

Test your knowledge by writing code to convey error messages as an array using the Maybe monad.

We'll cover the following...

Problem statement
Requirements
Sample inputs and outputs
Try it yourself
Solution
Explanation

Problem statement

In the previous lesson, we eliminated exceptions by rewriting the authenticateUser function as a two-track Either monad-based function.

This time, you have to rewrite the function featured there to utilize Maybe monad case analysis.

Requirements

By maintaining all the requirements stated in the previous challenge, you have to perform the following additional requirement in order to complete the challenge:

Convey each error message as an array with the error key by using the Maybe monad.

To reiterate, the requirements were:

If the provided username ...

Getting Started

An Introduction to Functional Programming in PHP

Core Concepts: Functional Programming in PHP

Composition and Helper Functions

Error Handling in Functional Programming

Functors in PHP

Parallelization of Tasks in PHP

Recursion, Pattern Matching, and Property Testing

Phonebook Application — A Simple Project

Conclusion

Appendix

Challenge 2: Error Messages Using Maybe Monad

Problem statement

Requirements