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
770
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
580
Ruby Trivia 3
sferik
0
720
The Value of Being Lazy
sferik
3
800
Ruby Trivia
sferik
2
1.3k
💀 Symbols
sferik
5
1.9k
Content Negotiation for REST APIs
sferik
8
1k
Writing Fast Ruby
sferik
629
62k
Mutation Testing with Mutant
sferik
5
1.1k
Other Decks in Programming
See All in Programming
CSC509 Lecture 04
javiergs
PRO
0
300
あなたとKaigi on Rails / Kaigi on Rails + You
shimoju
0
170
Domain-centric? Why Hexagonal, Onion, and Clean Architecture Are Answers to the Wrong Question
olivergierke
3
930
Claude Agent SDK を使ってみよう
hyshu
0
1.3k
テーブル定義書の構造化抽出して、生成AIでDWH分析を試してみた / devio2025tokyo
kasacchiful
0
230
TFLintカスタムプラグインで始める Terraformコード品質管理
bells17
2
330
「ちょっと古いから」って避けてた技術書、今だからこそ読もう
mottyzzz
11
6.9k
overlayPreferenceValue で実現する ピュア SwiftUI な AdMob ネイティブ広告
uhucream
0
200
NixOS + Kubernetesで構築する自宅サーバーのすべて
ichi_h3
0
1.1k
Go言語の特性を活かした公式MCP SDKの設計
hond0413
1
380
大規模アプリのDIフレームワーク刷新戦略 ~過去最大規模の並行開発を止めずにアプリ全体に導入するまで~
mot_techtalk
1
470
What's new in Spring Modulith?
olivergierke
1
160
Featured
See All Featured
[RailsConf 2023] Rails as a piece of cake
palkan
57
5.9k
個人開発の失敗を避けるイケてる考え方 / tips for indie hackers
panda_program
115
20k
JavaScript: Past, Present, and Future - NDC Porto 2020
reverentgeek
52
5.6k
Git: the NoSQL Database
bkeepers
PRO
431
66k
Balancing Empowerment & Direction
lara
5
690
Imperfection Machines: The Place of Print at Facebook
scottboms
269
13k
Designing for humans not robots
tammielis
254
26k
Exploring the Power of Turbo Streams & Action Cable | RailsConf2023
kevinliebholz
36
6.1k
Rebuilding a faster, lazier Slack
samanthasiow
84
9.2k
Fashionably flexible responsive web design (full day workshop)
malarkey
407
66k
Measuring & Analyzing Core Web Vitals
bluesmoon
9
630
The Web Performance Landscape in 2024 [PerfNow 2024]
tammyeverts
10
880
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.