Basic Logic in Ruby

In Ruby, you’ll find that all of the standard logic operators that most languages have, are supported.

Symbol	Meaning
<	Less than
>	Greater than
==	Equals
!=	Not equals
>=	Greater OR equal to
<=	Less OR equal to

Conditionals

Of course, conditionals such as an if statement are also possible within Ruby. Similar to Go, there are no parenthesis around the conditional statement.

stock = 1

if stock < 1
  puts "Sorry we are out of that item."
end # the end of our if statement

Notice that you also have an end statement, instead of braces like in C/C++/Java/Go.

The Else Statement

Likewise, you also have an else statement to go with your if statement.

For example you might have:

if stock < 1
  # the true block
  puts "Sorry we are out of that item."
else
  # the false block
  puts "Thank you for your order."
end

Else If Statements

Similar to Python, there is a special command for else if. It is the elsif keyword.

=begin

This will be used to show the entire possible If/Else If/Else block 
Look to see how we are using it.

=end
stock = 35

if stock < 1
  puts "Sorry we are out of that item."
elsif stock > 10
  # else if statement... if there are too many items give a discount to sell them
  puts "You get a special discount!"
else
  puts "Thank you for your order."
end

Notice Multiline Comments

Notice in this last block of code, there are multiple lines of comments. They start with the =begin and end with =end.

This is intuitive, but a bit verbose compared to many other languages.

Boolean Logic

Boolean logic operators for and (&&) and or (||) are the same as they are for most languages we’ve looked at.

Strings and Conditions

Strings in Ruby are case sensitive. So you need to test in a manner appropriate for what you are doing.

# check for case insensitivity
username  = "Walter"
expected_username = "walter"

if expected_username.downcase == username.downcase
  puts "Username is correct."
end

# check for case sensitivity
password = "123abc!"
expected_password = "123AbC!"

if expected_password == password
    puts "Password is correct."
end

Notice the use of downcase to send it to lower case. If you want a string to be all caps, use upcase.

Basic Logic in Ruby was originally found on Access 2 Learn