HackerRank Ruby Enumerables group

Hello coders, In this post, you will learn how to solve HackerRank Ruby Enumerables group_by Solution. This problem is a part of the Ruby Tutorial series. One more thing to add, don’t straight away look for the solutions, first try to solve the problems by yourself. If you find any difficulty after trying several times, then look for the solutions.

HackerRank Ruby Enumerables group_by Solution

Let’s get started with HackerRank Ruby Enumerables group_by Solution

Problem Statement

Another function often used with data collections is one which groups the elements according to some evaluation result.

Consider the following example. Let‘s say you have a list of 100 integers and you want to group them according to their even and odd value.

In Ruby, you can easily do this by using group_by method provide by Enumerable module.

> (1..5).group_by {|x| x%2}
{1=>[1,3,5], 0=>[2, 4]}

Of course this is a very simple example and its use can be very complicated in nature.

In this challenge, your task is to group the students into two categories corresponding to their marks obtained in a test. The list of students will be provided in a marks hash with student name as key and marks obtained (out of 100) as value pair, along with the pass_marks as argument.

The method group_by_marks must return a Hash containing an array of students who passed as value to Passed key, and those who failed as value to Failed key. If a particular key is empty, don’t return that key.

For example,

> marks = {"Ramesh":23, "Vivek":40, "Harsh":88, "Mohammad":60}
> group_by_marks(marks, 30)
=> {"Failed"=>[["Ramesh", 23]], "Passed"=>[["Vivek", 40], ["Harsh", 88], ["Mohammad", 60]]}

HackerRank Ruby Enumerables group_by Solution

def group_by_marks(marks, pass_marks)
  # your code here
  marks.group_by do |key, value|
    if key.empty? == false
      if value <= pass_marks
          "Failed"
      else
          "Passed"
      end
    end
  end       
end

Note: This problem (Ruby Enumerables group_by Solution) is generated by HackerRank but the solution is provided by Chase2Learn. This tutorial is only for Educational and Learning purpose.