Ruby Overview
Strings
Array Exercises
- An Array uses the familiar [a, b, c] format.
- Are sized dynamically and can be of mixed types. a = [‘string’, 1, :symbol]
Try typing this in IRB
a = [1, 2, 3]
a << 4 a[0]
a.first a.last
What do you think will happen?
“Chelsea will beat Liverpool”[0,1]
Hash Exercises
- A Hash looks like my_hash = {:a_symbol => 3, “a string” => 4}
- Are referenced like my_hash[:a_symbol] #=> 3
- like an associative map
Try typing this in IRB
currencies = {‘RWF’ => ‘Rwanda Franc’,
‘USD’ => ‘United States Dollar’}
currencies['RWF'] currencies['USD'] currencies['ABC']
Symbol Exercises
- A symbol looks like :this_is_a_symbol
- starts with a colon :
- can be used in similar places as a string but tells the interpreter and programmers that it means “the thing named :this_is_a_symbol” rather than text
- In ruby, we prefer symbols over hardcoded globals or strings. They’re very lightweight.
Try typing this in IRB
:rwanda
:ruby_on_rails