Covers basic ruby data types: Strings, arrays and hashes

1. Ruby Data Types
Dalal Alrayes
@dalrayes

2. Hi, I m Dalal

3. Everything is an Object
• An integer is an object 12
• A float is an object 1.333
• A string is an object “Ruby is awesome”
• An array is an object [“apple”,“orange”]
• A hash is an object { state: “Illinois”,
zipcode: “60606”}
• & many, other types (blocks, lambdas, modules,
classes) are also objects

4. Strings
• Anything surrounded by
• Text based characters, typically representing words
“Ruby is fun”
“I am a string”
“S”
• But can also be non-alphabet characters
“78”
“W2 2Sy”
quotes

5. String methods
• Start up your terminal
• Type ‘irb’
• Let’s look up the docs

6. Arrays
bulls = [“Rose”, “Butler”, “Gasol”, “Noah”, “Brooks”]
0 1 2 3 4
• Each element in the array is associated with and referred
to by an index
bulls[0] = ?
bulls[4] = ?
• Ordered, integer-indexed collection
• Can hold objects such as strings, integers, hashes and
other array objects

7. Indexing
array = [ “good”, “times”, 2015, “09”, “yup” ]
array[0] [1] [2] [3] [4]
array[-1][-2][-3][-4][-5]

8. Array methods
• Start up your terminal
• Type ‘irb’
• Let’s look up the docs (google: ruby docs array)

9. Hashes
• Dictionary like collection of unique key-value pairs
groceries = {
“apples” => 3,
“kale” => 1,
“chips” => 7
}
• Retrieve or create an entry by using its key
groceries[“apples”]
groceries[“ice cream”] = 2

10. Hashes, ctd
• Implicit Form
groceries = {“apples” => 3, “kale” => 1}
• Symbols
groceries = {apples: 3, kale: 1}
style = {color: “red”, size: 3}

11. Hash methods
• Start up your terminal
• Type ‘irb’
• Let’s look up the docs (try google: ruby 2.2 docs
hash)

12. • Everything is an object
• Strings are anything in between quotes
• Arrays are indexed and start at 0
• Hashes are unique key-value pairs
• Check the official ruby docs for methods for
each!
Recap