Upgrade to Pro
— share decks privately, control downloads, hide ads and more …
Speaker Deck
Features
Speaker Deck
PRO
Sign in
Sign up for free
Search
Search
Ruby Trivia 2
Search
Erik Berlin
November 05, 2015
Programming
0
720
Ruby Trivia 2
Presented at the Berlin Ruby User Group (RUG::B) on November 5, 2015.
Erik Berlin
November 05, 2015
Tweet
Share
More Decks by Erik Berlin
See All by Erik Berlin
Enumerator::Lazy
sferik
2
540
Ruby Trivia 3
sferik
0
680
The Value of Being Lazy
sferik
3
740
Ruby Trivia
sferik
2
1.3k
💀 Symbols
sferik
5
1.9k
Content Negotiation for REST APIs
sferik
8
960
Writing Fast Ruby
sferik
628
61k
Mutation Testing with Mutant
sferik
5
1.1k
Other Decks in Programming
See All in Programming
Kubernetesで実現できるPlatform Engineering の現在地
nwiizo
3
1.9k
マルチアカウント環境での、そこまでがんばらない RI/SP 運用設計
wa6sn
0
710
AHC 044 混合整数計画ソルバー解法
kiri8128
0
330
[NG India] Event-Based State Management with NgRx SignalStore
markostanimirovic
1
110
Compose Hot Reload is here, stop re-launching your apps! (Android Makers 2025)
zsmb
1
480
いまさら聞けない生成AI入門: 「生成AIを高速キャッチアップ」
soh9834
15
4.5k
エンジニア未経験が最短で戦力になるためのTips
gokana
0
260
リアルタイムレイトレーシング + ニューラルレンダリング簡単紹介 / Real-Time Ray Tracing & Neural Rendering: A Quick Introduction (2025)
shocker_0x15
1
290
フロントエンドテストの育て方
quramy
11
2.9k
Do Dumb Things
mitsuhiko
0
430
Code smarter, not harder - How AI Coding Tools Boost Your Productivity | Webinar 2025
danielsogl
0
120
Boost Your Performance and Developer Productivity with Jakarta EE 11
ivargrimstad
0
1.3k
Featured
See All Featured
4 Signs Your Business is Dying
shpigford
183
22k
Creating an realtime collaboration tool: Agile Flush - .NET Oxford
marcduiker
30
2k
What's in a price? How to price your products and services
michaelherold
245
12k
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
panda_program
104
19k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
32
5.1k
How GitHub (no longer) Works
holman
314
140k
The Myth of the Modular Monolith - Day 2 Keynote - Rails World 2024
eileencodes
23
2.6k
How to Think Like a Performance Engineer
csswizardry
23
1.5k
Embracing the Ebb and Flow
colly
85
4.6k
Dealing with People You Can't Stand - Big Design 2015
cassininazir
367
26k
Bash Introduction
62gerente
611
210k
Visualization
eitanlees
146
16k
Transcript
Ruby Trivia 2
What is the return value of Ruby’s method visibility keywords?
private, public, protected Question 1:
self Answer 1: Ruby’s method visibility keywords can be used
as r-values.
Given a button method that takes an argument and a
block, which of these are valid Ruby? button "string" { |n| n } button "string" do |n| n end button ["string"] { |n| n } button ["string"] do |n| n end Question 2:
All except: button("string") { |n| n } Answer 2:
How could this line be fixed? button("string") { |n| n
} Bonus Question:
How could this line be fixed? button("string") { |n| n
} Bonus Question: Answer: Add parentheses around the argument.
What is the result of this line: a Hash with
a String key, a Hash with a Symbol key, or a SyntaxError? {"key": "What happens?"} Question 3:
a Hash with a Symbol key* Answer 3: *In Ruby
2.2 and later. In earlier versions, it raises a SyntaxError.
What is the value of each argument? def foo(*w, a:
7, **t) puts "w: #{w}, a: #{a}, t: #{t}" end foo({a: 1, b: 2, "c" => 3, d: 4}) Question 4:
w: [{"c" => 3}] a: 1 t: {:b => 2,
:d => 4} Answer 4:
What happens if you add a positional argument to the
end? def foo(*w, a: 7, **t) puts "w: #{w}, a: #{a}, t: #{t}" end foo({a: 1, b: 2, "c" => 3, d: 4}, 5) Bonus Question:
What happens if you add a positional argument to the
end? w: [{:a=>1, :b=>2, "c"=>3, :d=>4}, 5] a: 7 t: {} Bonus Question:
When you inspect Object.new, Ruby outputs something like: #<Object: 0x00c1a551f1ab1e>
What are the properties and significance of this hex number? Question 5:
1. It’s the object’s address in memory. 2. It’s always
even. 3. It’s double the object’s object_id. Answer 5:
Answer 5:
Thanks for playing! Follow @sferik on Twitter for more Ruby
trivia and practica.