Variable in Ruby

The variable is where we can store some value to perform a manipulation.

Considering that we have 99 chocolates, we want to divide it by 9 to find out how many people will receive each chocolate.

total_cho = 99
 => 99
person = 9
 => 9
 each_person = 99/9
 => 11

Naming Convention:

There is no space between the variables.

There is no special character expect _(underscore). eg each_person

A variable name can have a number but a variable can not start with the number.

The capital character should not appear at the start of the variable.

fruit = "banana"
 => "banana" 
fruit123 = "apple"
 => "apple" 
fruitType = "summer seasonal"
 => "summer seasonal" 
_fruit = "kiwi"
 => "kiwi"

The underscore — a special variable:

If you want to use the last manipulate output so with the help of underscore we can use it.

data = 798
 => 798 
3.0.0 :014 > data += 4569
 => 5367 
3.0.0 :015 > value = _
 => 5367

Constants:

A constant can be thought of as a variable whose value doesn’t change. Constant in Ruby start with a capital letter.

Pi = 3.14
 => 3.14
r = 3
 => 3
Pi*r**2
 => 28.26

 Pi = 3.14
(irb):24: warning: already initialized constant Pi
(irb):21: warning: previous definition of Pi was here
 => 3.14