There's no better way to learn a new programming language than just writing code. Having just transitioned from JavaScript to Ruby for the first time, I found myself struggling to find the right method for the job.

Websites like LeetCode and codewars are great for grinding out practice, so I decided to start logging which methods I needed to use and how often. To my surprise, I didn't wind up using the same method more than once across the first 10 Ruby problems I came across on codewars.

Some of these answers I came up with on my own while several others were listed under "Best Practices". Here's my running list of common Ruby methods. I'll update the list as I continue to complete problems in hopes of curating a list of some of the most common and fundamental Ruby methods.

delete

Problem for Context
Documentation

The delete method takes an object as an argument and deletes everything from self that is equal to the object. I used the delete method below to remove all vowels from a given string:

def disemvowel(str)
  str.delete "aeiouAEIOU"
end

slice!

Problem for Context
Documentation

The slice! method differs from slice in an important way. slice returns the element at a specified index while slice! deletes the element at the specified index and returns the deleted object. I used slice! to remove the first and last characters in a string:

def remove_char(s)
  s.slice!(0)
  s.slice!(-1)
  s
end

even? and odd?

Problem for Context
Documentation

These are extremely simple methods that can be called directly on integers (since everything in Ruby is an object). I'm used to using % 2 in JavaScript to determine if a number is even or odd, but Ruby simplifies that process immensely. I used .even in a ternary to solve this problem:

def even_or_odd(number)
  number.even? ? "Even" : "Odd"
end

method

Problem for Context
Documentation

This is one that I have to keep reading the documentation on. As I understand it, method can be called on an object and, in doing so, creates an object that can be used to invoke a method elsewhere. Here's an example provided by the documentation:

class Thing
  def square(n)
    n*n
  end
end
thing = Thing.new
meth  = thing.method(:square)

meth.call(9)                 #=> 81
[ 1, 2, 3 ].collect(&meth)   #=> [1, 4, 9]

In this example, calling method on thing allows the square method to be called later on. I used method to build a basic calculator:

def basic_op(operator, value1, value2)
  value1.method(operator).(value2)
end

split

Problem for Context
Documentation

split is a handy method to keep in your back pocket if you ever need to iterate over a string. split takes a delimiter as an argument and separates a string into substrings based on that delimiter. I used split to break apart a sentence string into individual words in order to determine which word was shortest:

def find_short(s)
  lengths = []
  s.split(" ").each do |w|
    lengths.push(w.length)
  end
  return lengths.min
end

min and max

Problem for Context
Documentation

min and max are simple range methods that return the maximum or minimum value in a range, respectively. They're exceptionally easy to use and much more straightforward than their JavaScript counterparts. I used max and min to write a few simple range functions:

def min(list)
  list.min
end

def max(list)
  list.max
end

to_i

Problem for Context
Documentation

The to_i will convert a string to an integer when called on a string. Again, calling the conversion method directly on the object itself makes running the conversation very simple. I used to_i to parse an integer from a string:

def get_age(age)
  age[0].to_i
end