Learning outcome - Thur 12th March, 2020

What learning outcomes did you focus on today? What did you learn?

I moved up a level, and began solving the mid-level ruby Algorithm on Exercism.io. I must confess that this level is a bit tougher but it is also very Interesting at the same time. I have had the chances to crack by brains and solve Algorithms with a test first approach. I also got familiar with wide range of syntax in ruby and its usage.

1. The Set Intersection (&) symbol - Returns a new array containing unique elements common to the two arrays. The order is preserved from the original array.

   Example:

   arr_1 = [1,2,3,4,6,8]

   arr_2 = [2,3,9,0,5,4] arr_1 & arr_2 => [2, 3, 4]

2. .gsub (pattern, replacement) - Returns a copy of str with all occurrences of pattern substituted for the second argument. The pattern is typically a Regexp; if given as a String, any regular expression meta-characters it contains will be interpreted literally, It works for digits too, all you have to do is g

   Example:

   - If you want to eliminate symbols from a string and return a new string with just letters

   string = O-W-R-C

   new_string = string.gsub(/\W/, ' ') => OWRC

3. .sum enumerable - Returns the sum of elements in an Enumerable. If a block is given, the block is applied to each element before addition.

   Example:

   - Return the total sum of the value in the giving array multiplied by 2?

   - normally I will solve it like this

   array = [1,2,3,4,5,6]

   def array

   total = 0

   array.each do | i |

   result = i * 2

   total += result

   end

   total

   end

   - New Approach using the sum method

   array = [1,2,3,4,5,6]

   def array

   result = array.each.sum

   end

   result

   With the second solution, you are allowing ruby do the sum for you while looping and append the total in the result variable

4. Splat Operator (*) - Splat operator allows us to work with an undefined number of arguments. It also converts the arguments to an array within a method.

What's something that surprised you today?

- There’s always a better or simpler way to solve a problem, thats certain.

- Solving Katas is becoming fun for me.

- The moment where I get stuck and start cracking my head for ideas to a solution or when i have go back to the documentation to lookup a method or ask my colleague for an idea, is the process where a lot of learning happens.

What's something that frustrated you today?

Started solving the medium level Katas, and I must confess that there’s a lot of head cracking involve 😀

Reference

Ruby-docs

Exercism.io

Parameter with splat operator (*) in Ruby