Arrays in Ruby

An array is just a list in your computer. Every slot in the list acts like a variable: you can see what object a particular slot points to, and you can make it point to a different object. Arrays are best explained by the following example Arrays.rb.

# Arrays

# Empty array
var1 = []
# Array index starts from 0
puts var1[0]

# an array holding a single number
var2 = [5]
puts var2[0]

# an array holding two strings
var3 = ['Hello', 'Goodbye']
puts var3[0]
puts var3[2]

flavour = 'mango'
# an array whose elements are pointing
# to three objects - a float, a string and an array
var4 = [80.5, flavour, [true, false]]
puts var4[2]

name = ['Satish', 'Talim', 'Ruby', 'Java']
puts name[0]
puts name[1]
puts name[2]
puts name[3]
# the next one outputs nil
# nil is Ruby's way of saying nothing
puts name[4]
# we can add more elements too
name[4] = 'Pune'
puts name[4]
# we can add anything!
name[5] = 4.33
puts name[5]
# we can add an array to an array
name[6] = [1, 2, 3]
puts name[6]

# some methods on arrays
newarr = [45, 23, 1, 90]
puts newarr.sort
puts newarr.length

# method each (iterator) - extracts each element into lang
languages = ['Pune', 'Mumbai', 'Bangalore']

languages.each do |lang|
  puts 'I love ' + lang + '!'
  puts 'Don\'t you?'
end

The method each allows us to do something (whatever we want) to each object the array points to. In the example, we are able to go through each object in the array without using any numbers.

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