Any fool can write code that a computer can understand. Good programmers write code that humans can understand. ― Martin Fowler

Ruby is... “A dynamic, open source programming language with a focus on simplicity and productivity. It has an elegant syntax that is natural to read and easy to write.”

The reason I enjoy Ruby is because it’s a beautiful language that is human friendly and fun, it was actually the first programming language I ever learned.

It was a great stepping stone into other programming languages like JavaScript and it has certain commonalities with JS as well as others, for example the if statement.

How does an if statement work?

The first thing we need to talk about before I answer the question of how an If statement works is control flow. Control Flow is used to change the flow of control in any given program based on certain conditions and If statements do just that. If statements are evaluated on truthy or falsy expressions, if the evalution results to true than the code inside the block will be run until the end.

my_bank_account = 100

if my_bank_account_balance > 50
   puts "I'm eating steak!"
end

Since our bank account has over 50 dollars in it well we could get that steak dinner. YUM!! - (Assuming your not a veg-head :) )

Another keyword that may be used in our If statement is else and it leads to a path for a program to resume if the conditions for an if statement have not been met resulting in a falsy value. Let’s take our example from above and implement it below:

my_bank_account = 25

if my_bank_account_balance > 50
   puts "I'm eating steak!"
else
     puts "I'm eating a slice of pizza"
end

As you can see that our bank account has less than 50 dollars in it so we cannot afford that steak dinner so in this case our If statement will puts out “I’m eating a slice of pizza”, (Maybe next time)

You can take this one step further & use an elsif statement:

my_bank_account = 25

if my_bank_account_balance > 50
  puts "I'm eating steak!"
elsif my_bank_account == 30
  puts "Olive Garden it is"
else
  puts "I'm eating a slice of pizza"
end

This is saying “If” my_bank_account is greater than 50 print this message, elsif my_bank_account equals 30 print this special message, otherwise if none of these conditions are true then print the “I’m eating pizza” message.”

The cool thing about If statements is that we can have nested If statements inside another. Let’s take an example:

if 5 < 10
  puts "I'm less than you"
  if 5 > 10
       puts "I'm higher than you"
  else
       puts "I'm half the size of that other digit"
  end
end

It will puts out the “I’m less than you” and “I’m half the size of that other digit” because the first If statement 5 < 10 is truthy so it will puts “I’m less than you” and still go into the nested If statement.

Ruby operators - specifically &&, ||, and ==

Next I want to describe some Ruby operators, first up is the && operator which is called the double-ampersand which represents “AND”. For this operator to be true both values must equate to true.

true && true #=> true
false && true #=> false

Next up is the ||double-pipe which represents “OR”. For the double-pipe to evalute to true we only need one value to equate to true, like so:

true || false #=> true

Last but not least is the == comparison operator represented by the double equal signs. This operator is checking for equality not to be confused with = assignment operator which simply assigns values. The comparison operator checks to see If two values are equal, then the statement will return true, If they are not equal, then it will return false:

2 == 2 #=> true
1 == 2 #=> false

What does erb do and what does it take as an argument?

In this portion I want to touch on erb which stands for Embedded Ruby, erb is a templating engine, which comes standard with every Ruby installation that allows us to use a combination of HTML and Ruby. Well you might say, OK, “so how does this benefit me?”, so glad you asked, erb allows us to reduce duplication of HTML as well as generate content that can change based on the available data. We can implement erb into our code in two ways, the first is the the substitution tag (<%=). It starts with an opening tag delimiter and equals sign (<%=) and ends with a closing tag delimiter (%>). It must contain a snippet of Ruby code that resolves to a value; if the value isn’t a string, it will be automatically converted to a string using its to_s method.

`<%= @verse.title %>`

The second of the two is the Scripting Tags, The scripting tags open with <% and it also closes with a %>. They evaluate Ruby code but never actually display Ruby code, in other words thess tags execute the code it contains, but doesn’t insert a value into the output. (cool right!)

Scripting tags can have some affect on iterative or conditional expressions even if the expression is untagged text they surround, for example:

<% if @flatironschool == true %>
      flatironschool
    <% end %>

What does redirect do and what does it take as an argument how is it different from erb’s argument?

I’m going to wrap this article up by talking about redirect a redirect takes in a path as an arguement, it will tell your browser it needs to make a new request to a different location and this location can be a new path in your Web application or it can be a url. If you wanted to redirect to your login page for example it can be done like this:

redirect "/login"

If you wanted to redirect to a new url it would look like this:

redirect "https://hashnode.com"

A redirect is different from erb. A redirect makes a new request and an erb is most commonly seen rendering web pages. The difference in arguements are as follows - a redirect takes us to a new path, and an erb’s arguement is a new page to be rendered.

Redirect

redirect '/signup" #<= redirecting to new path

ERB

erb :'/users/signup.html' #<= rendering a new page

That concludes this article I hope you’ve learned something today.

Happy Coding!!! :)