Ruby language overview
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Ruby is an object-oriented scripting language with features like mixins, metaprogramming, and dynamic typing. It allows defining functions and methods that can take blocks or lambdas as arguments. Arrays, hashes, and ranges provide ways to iterate over collections. Strings support interpolation and methods like split. Classes define methods that can access fields and local variables. The JSON library extends core types like Hash to add methods like to_json for serialization.
![Arrays, hashes, ranges
# List of string, float, string, int and hash
array = ["Hello", 3.14, "ruby", 1, {hello: "hi"}]
for i in array
puts i
end
>> Hello
>> 3.14
>> ruby
>> 1
>> {:hello=>"hi"}](https://image.slidesharecdn.com/0xyvmg2wrcas9uaz0dju-signature-da3b1296349789a0ad64ffbdfa6ace75bc9204241f328a30aaca54db6d760f2a-poli-170220153616/85/Ruby-language-overview-6-320.jpg)
![Bonus
reponse = {
title: "Harry Potter and the Gradle Build",
description: "Book by J.K. Rowling",
attrs: {
pages: 192,
worth_reading: true
},
reviews: [ "Awesome!", "Great" ]
}
puts reponse.to_json
NoMethodError: undefined method `to_json' for #<Hash:0x007fcdb18f84b0>
from (irb):19
from /usr/bin/irb:12:in `<main>'](https://image.slidesharecdn.com/0xyvmg2wrcas9uaz0dju-signature-da3b1296349789a0ad64ffbdfa6ace75bc9204241f328a30aaca54db6d760f2a-poli-170220153616/85/Ruby-language-overview-13-320.jpg)
![Bonus (Extension functions)
require "json" #
...
puts reponse.to_json
{
"title": "Harry Potter and the Gradle Build",
"description": "Book by J.K. Rowling",
"attrs": {
"pages": 192,
"worth_reading": true
},
"reviews": [
"Awesome!",
"Great"
]
}](https://image.slidesharecdn.com/0xyvmg2wrcas9uaz0dju-signature-da3b1296349789a0ad64ffbdfa6ace75bc9204241f328a30aaca54db6d760f2a-poli-170220153616/85/Ruby-language-overview-14-320.jpg)
Ruby language overview
- 3. Alright, simple enough a = "Hello, Ruby" puts a => "Hello, Ruby"
- 5. Method calls without parentheses def plus(a, b) a+b end plus 1, 2 # WAT => 3
- 6. Arrays, hashes, ranges # List of string, float, string, int and hash array = ["Hello", 3.14, "ruby", 1, {hello: "hi"}] for i in array puts i end >> Hello >> 3.14 >> ruby >> 1 >> {:hello=>"hi"}
- 7. Arrays, hashes, ranges for i in 1..10 puts i end for i in 'a'..'z' puts i end 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z
- 8. Arrays, hashes, ranges # split(¡° ¡°) puts %w(I still love you Kotlin) "I", "still", "love", "you", "Kotlin"
- 9. String interpolation a = 1 b = 4 puts "The number #{a} is less than #{b}" puts "%0.5d" % 5 >> "The number 1 is less than 4" >> "00005"
- 10. Blocks (lambdas) 5.times do |x| puts "x inside the block: #{x}" end ('a'..'z').each {|i| puts i} >> x inside the block: 0 >> x inside the block: 1 >> x inside the block: 2 >> x inside the block: 3 >> x inside the block: 4 a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p, q, r, s, t, u, v, w, x, y, z
- 11. Functional programming array.length.downto(1).map {|n| "I said #{n}"}
- 12. Classes and methods class Sample < Base def hello puts "Hello Ruby!" @field = "Field" local = "Local variable" end end
- 13. Bonus reponse = { title: "Harry Potter and the Gradle Build", description: "Book by J.K. Rowling", attrs: { pages: 192, worth_reading: true }, reviews: [ "Awesome!", "Great" ] } puts reponse.to_json NoMethodError: undefined method `to_json' for #<Hash:0x007fcdb18f84b0> from (irb):19 from /usr/bin/irb:12:in `<main>'
- 14. Bonus (Extension functions) require "json" # ... puts reponse.to_json { "title": "Harry Potter and the Gradle Build", "description": "Book by J.K. Rowling", "attrs": { "pages": 192, "worth_reading": true }, "reviews": [ "Awesome!", "Great" ] }