Ruby class Array | Chautauqua

Creating

# arr = [1,'b',:dig]

%warr = %w[a b c] # ['a','b','c'] Documentation Playground

arr = Array.new(3)

[nil, nil, nil]

Methods

Creating an Array

[]Array[1, 'a', :dig] # [1,'a',:dig] Documentation Playground

Array[1, 'a', :dig]

[1, "a", :dig]

newArray.new([1, 'b', :dig]) # [1,'b',:dig] Documentation Playground

Array.new([1, 'b', :dig])

[1, "b", :dig]

new(count)Array.new(2) # [nil,nil] Documentation Playground

Array.new(2, 'a')

[nil, nil]

new(count,val)Array.new(2, 'a') # ['a','a'] Documentation Playground

Array.new(2, 'a')

["a", "a"]

newArray.new(2) {|i| "E#{i}" } # ['E0','E1'] Documentation Playground

Array.new(3) {|i| "E#{i}" }

["E0", "E1", "E3"]

try_convertArray.try_convert([1, 2]) # [1,2] or nil Documentation Playground

Array.try_convert([1, 2, 3]).inspect + '; ' +
Array.try_convert('Not an array').inspect

[1, 2, 3]; nil

Querying

all?[1, 1, 1].all?(1) # true Documentation Playground

['dig', 'dim', 'diz'].all?(/di/)

true

any?[1, 2, 3].any?(2) # true Documentation Playground

[1, 2, 3].any?(2)

true

count[1, 2, 3].count # 3 Documentation Playground

[1, 2, 3].count

3

empty?[1, 2, 3].empty? # false Documentation Playground

[1, 2, 3].empty?

false

index (alias find_index)['a', 'b', 'c', 'c'].index('c') # 2 Documentation Playground

['a', 'b', 'c', 'c'].index('c')

2

rindex['a', 'b', 'c', 'c'].rindex('c') # 3 Documentation Playground

['a', 'b', 'c', 'c'].rindex('c')

3

hash['a', 'b', 'c'].hash # 6345789 (differs) Documentation Playground

['a', 'b', 'c'].hash

include?[1, 2, 3].include?(2) # true Documentation Playground

[1, 2, 3].include?(2)

true

none?[1, 2, 3].none?(7) # true Documentation Playground

['dig', 'dim', 'diz'].none?(/do/)

true

one?(count)[1, 2, 3].one?(2) # true Documentation Playground

[1, 2, 3].one?(2)

true

size (alias length)[1, 2, 3].size # 3 Documentation Playground

[1, 2, 3].size

3

Comparing

<=>[0, 1, 2] <=> [0, 1, 2] # 0 (-1,0,1) Documentation Playground

[0, 1, 2] <=> [0, 1, 2]

0

==[0, 1, 2] == [0, 1, 2] # true Documentation Playground

[0, 1, 2] == [0, 1, 2]

true

eql?[0, 1, 2].eql?([0, 1, 2]) # true Documentation Playground

[0, 1, 2].eql?([0, 1, 2])

true

Fetching

[] (alias slice)!arr[1] or arr.slice(1) # b Documentation Playground

arr=[1, 'a', :dig]
arr[0].inspect

1

assoc[1, 'a', [5,6]].assoc(5) # [5,6] Documentation Playground

[1, 'a', [5,6], [5,12]].assoc(5)

[5, 6]

rassoc[1, 'a', [5,6]].rassoc(6) # [5,6] Documentation Playground

[1, 'a', [5,6], [5,9], [5,12,7]].rassoc(12)

[5, 12, 7]

atarr.at(0) # 1 Documentation Playground

arr=[1, 'b', :dig]
arr.at(0).inspect

1

bsearch[0, 6, 7].bsearch {|x| x >= 4 } # 6 Documentation Playground

[0, 6, 7].bsearch {|x| x >= 4 }

6

bsearch_index[0, 6, 7].bsearch_index {|x| x >= 4 } # 1 Documentation Playground

[0, 6, 7].bsearch_index {|x| x >= 4 }

1

compact![nil, 2, 2, nil, 3].compact # [2,2,3] Documentation Playground

[nil, 2, 2, nil, 3].compact

[2, 2, 3]

dig['a',2,[1,[3,4]]].dig(2, 1) # [3,4] Documentation Playground

['a',2,[1,[3,4]]].dig(2, 1).inspect

[3, 4]

droparr.drop(1) # ['b',:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.drop(1)

["b", :dig]

drop_while[0, 1, 6, 7].drop_while {|x| x<=4} # [6,7] Documentation Playground

[0, 1, 6, 7].drop_while {|x| x <= 4}

[6, 7]

fetcharr.fetch(2) # :dig Documentation Playground

arr=[1, 'b', :dig]
arr.fetch(2)

:dig

fetch_valuesarr.fetch_values(2,0) # [:dig,1] Documentation Playground

arr=[1, 'a', :dig]
arr.fetch_values(2,0)

[:dig, 1]

first(count)arr.first(2) # [1,'b'] Documentation Playground

arr=[1, 'b', :dig]
arr.first(2)

[1, "b"]

last(count)arr.last(2) # ['b',:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.last(2)

["b", :dig]

max(count)[2,0,3,1].max # 3 Documentation Playground

[2,0,3,1].max

3

min(count)[2,0,3,1].min # 3 Documentation Playground

[2,0,3,1].min

3

minmax[2,0,3,1].minmax # [0,3] Documentation Playground

[2,0,3,1].minmax

[0, 3]

reject!arr.reject {|e| e.to_s[0]=='b'} # [1,:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.reject {|e| e.to_s.start_with?('b') }

[1, :dig]

reverse!arr.reverse # [:dig,'b',1] Documentation Playground

arr=[1, 'b', :dig]
arr.reverse

[:dig, "b", 1]

rotate(count)!arr.rotate(1) # ['b',:dig,1] Documentation Playground

arr=[1, 'b', :dig]
arr.rotate(1)

["b", :dig, 1]

sample(count)arr.sample # (random) Documentation Playground

arr=[1, 'b', :dig]
arr.sample(2)

[random, random]

select!arr.select {|e| e.to_s[0]=='b'} # b Documentation Playground

arr=[1, 'b', :dig, :big, 'bugger']
arr.select {|e| e.to_s.start_with?('b') }

["b", :big, "bugger"]

shuffle!arr.shuffle # [random,random,random] Documentation Playground

arr=[1, 'b', :dig]
arr.shuffle

[random, random, random]

sort![3, 0, 1, 2].sort # [0,1,2,3] Documentation Playground

[3, 0, 1, 2].sort

[0, 1, 2, 3]

take[0,1,2,3,4].take(3) # [0,1,2] Documentation Playground

[0,1,2,3,4].take(3)

[0, 1, 2]

take_while[1,2,3,4].take_while {|e| e < 3 } # [1,2] Documentation Playground

[1,2,3,4].take_while {|e| e < 3 }

[1, 2]

uniq![1,1,2,3,3].uniq # [1,2,3] Documentation Playground

[1,1,2,3,3].uniq

[1, 2, 3]

values_at!arr.values_at(2,0) # [:dig,1] Documentation Playground

arr=[1, 'b', :dig]
arr.values_at(2,0)

[:dig, 1]

Assigning

<<arr << 'dog; # [1,'a',:dig,'dog'] Documentation Playground

arr=[1, 'b', :dig]
arr<<'dog'

[1, "a", :dig, "dog"]

[]=arr[2] = 'dog' # [1,'a','dog'] Documentation Playground

arr=[1, 'b', :dig]
arr[2] = 'dog'

[1, "a", "dog"]

concatarr.concat([3, :cat]) # [1,'b',:dig,3,:cat] Documentation Playground

arr=[1, 'b', :dig]
arr.concat(['dog', :cat])

[1, "b", :dig, "dog", :cat]

fillarr.fill('-', 1, 2) # [1,'-','-'] Documentation Playground

arr=[1, 'b', :dig]
arr.fill('-', 1, 2)

[1, "-", "-"]

replace .initialize_copyarr.replace(['fox','cat']) # ['cat','rat'] Documentation Playground

arr=[1, 'b', :dig]
arr.replace(['fox','cat','bee'])

["fox", "cat", "bee"]

insertarr.insert(1,:bee,3) # [1,:bee,3,'b',:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.insert(1, :bee, 3)

[1, :bee, 3, "b", :dig]

append (alias push)arr.append(:bee,3) # [1,'b',:dig,:bee,3] Documentation Playground

arr=[1, 'b', :dig]
arr.append(:bee,3)

[1, "b", :dig, :bee, 3]

prepend (alias unshift)arr.prepend(:bee,3) # [:bee,3,1,'b',:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.prepend(:bee,3)

[:bee, 3, 1, "b", :dig]

sort_by!arr.sort_by! {|e| e.size } # ['b',:dig,1] Documentation Playground

arr=[1, 'b', :dig]
arr.sort_by! {|e| e.size }

["b", :dig, 1]

! See non-bang methods for:

flatten! reverse! rotate! shuffle! sort!

Deleting

cleararr.clear # [] Documentation Playground

arr=[1, 'b', :dig]
arr.clear

[]

deletearr.delete('b') # [1,:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.delete('b').inspect + '; ' + arr.inspect

"b"; [1, :dig]

delete_ifarr.delete_if {|e| e.to_s[0]=='d'} # [1,'b'] Documentation Playground

arr=[1, 'b', :dig]
arr.delete_if {|e| e.to_s[0]=='d'}

[1, "b"]

keep_ifarr.keep_if {|e| e.to_s[0]=='d'} # [:dig] Documentation Playground

arr=[1, 'b', :dig]
arr.keep_if {|e| e.to_s[0].length==1}

[1, "b"]

pop(count)arr.pop # :dig Documentation Playground

arr=[1, 'b', :dig]
arr.pop(2).inspect

["b", :dig]

shift(count)arr.shift # 1 Documentation Playground

arr=[1, 'b', :dig]
arr.shift(2).inspect + '; ' + arr.inspect

[1, "b"]; [:dig]

! See non-bang methods for:

compact! reject! select!→(alias filter!) slice!→(see []) uniq!

Combining

&[0,1,2,3] & [1,2] # [1,2] Documentation Playground

[0, 1, 2, 3] & [1, 2]

[1, 2]

+[0,1] + [2,3] # [0,1,2,3] Documentation Playground

[0,1] + [2,3]

[0, 1, 2, 3]

-[1,1,1,2,3] - [1] # [2,3] Documentation Playground

[1,1,1,2,3] - [1]

[2, 3]

|[1,1,2] | [3,3,4] # [1,2,3,4] Documentation Playground

[1,1,2] | [3,3,4]

[1, 2, 3, 4]

difference[1,1,2,3,1].difference([1]) # [2,3] Documentation Playground

[1,1,2,3,1].difference([1])

[2, 3]

intersection[0,1,2].intersection([2,1]) # [1,2] Documentation Playground

[0,1,2].intersection([2,1])

[1, 2]

product[1].product([2,3,7]) # [[1,2],[1,3],[1,7]] Documentation Playground

[0,1].product([2,3])

[[0, 2], [0, 3], [1, 2], [1, 3]]

union[0,1,1].union([2,1],[3,1]) # [1,2] Documentation Playground

[0,1,1].union([2,1],[3,1])

[0, 1, 2, 3]

Iterating

combination[1,2,3].combination(2){|c|p c} # [1,2][1,3]… Documentation Playground

a=[];[1,2,3].combination(2) {|c|a<<c}.inspect + '; ' + a.inspect

[1, 2, 3]; [[1, 2], [1, 3], [2, 3]]

cycle(count|FOREVER)[0,1].cycle(2){|c|p c} # 0;1;0;1 Documentation Playground

WARN: No count is cycle forever…
a=[];[1,2,3].cycle(2) {|c|a<<c}.inspect + '; ' + a.inspect

nil; [1, 2, 3, 1, 2, 3]

each[1,2,3].each{|c|p c} # 1;2;3 Documentation Playground

s='';['a','b','c'].each {|c| s += c.to_s}.inspect+ '; ' + s

["a", "b", "c"]; abc

each_indexarr.each_index{|i|p i} # 0;1;2 Documentation Playground

s='';a=['a','b','c'];a.each_index {|i| s += "#{i}-#{a[i]};"}.inspect+ '; ' + s

["a", "b", "c"]; 0-a;1-b;2-c;

permutation[0,1].permutation(2){|c|p c} # [0,1];[1.0] Documentation Playground

s='';[0,1,2].permutation(2) {|c| s += c.to_s}.inspect+ '; ' + s

[0, 1, 2]; [0, 1][0, 2][1, 0][1, 2][2, 0][2, 1]

repeated_combination[0,1].repeated_combination(1){…} # [0,0]… Documentation Playground

s='';[0,1,2].repeated_combination(2) {|c| s += c.to_s}.inspect+ '; ' + s

[0, 1, 2]; [0, 0][0, 1][0, 2][1, 1][1, 2][2, 2]

repeated_permutation[0,1].repeated_permutation(1){…} # [0,0]… Documentation Playground

s='';[0,1,2].repeated_permutation(2) {|c| s += c.to_s}.inspect+ '; ' + s

[0, 1, 2]; [0, 0][0, 1][0, 2][1, 0][1, 1][1, 2][2, 0][2, 1][2, 2]

reverse_each[0,1].reverse_each(1){|c|p c} # [0];[1] Documentation Playground

s='';[0,1,2].reverse_each(2) {|c| s += c.to_s}.inspect+ '; ' + s

[0, 1, 2]; [0, 0][0, 1][0, 2][1, 1][1, 2][2, 2]

Converting

map (alias collect)arr.map{|e| e.class} # [Int…,String,Symbol] Documentation Playground

arr=[1, 'b', :dig]
arr.map {|e| e.class}

[Integer, String, Symbol]

flatten[0, [1,2]].flatten # [0,1,2] Documentation Playground

[0, [1,2], [3,4,5]].flatten

[0, 1, 2, 3, 4, 5]

to_s (alias inspect)arr.to_s # '[1,\"b\",:dig]' Documentation Playground

arr=[1, 'b', :dig]
arr.to_s.inspect

"[1, \"b\", :dig]"

joinarr.join('|') # 1|b|dig Documentation Playground

arr=[1, 'b', :dig]
arr.join('|')

1|b|dig

to_aa=MyA.new([1,2]);a.to_a (.class) # MyA;Array Documentation Playground

class MyArr < Array; end; MyArr.new([1,2]).class.inspect + '; ' + MyArr.new([1,2]).to_a.class.inspect

MyArr; Array

to_arya=MyA.new([1,2]);a.to_ary (.class) # MyA;MyA Documentation Playground

class MyArr < Array; end; MyArr.new([1,2]).class.inspect + '; ' + MyArr.new([1,2]).to_ary.class.inspect

MyArr; MyArr

to_h[['a',0],['b',1]].to_h # {'a'=>0,'b'=>1} Documentation Playground

[['a',0], ['b',1]].to_h.inspect

{"a" => 0, "b" => 1}

transpose[['a',0],…].transpose # [['a','b'],[0,1]] Documentation Playground

[['a',0], ['b',1]].transpose.inspect

[["a", "b"], [0, 1]]

zip[0].zip(['a'],[:c]) # [[0,'a',:c]] Documentation Playground

[0,1].zip(['a','b'],[:c,:d])

[[0, "a", :c], [1, "b", :d]]

! See non-bang methods for:

map!→(alias collect!)

Other Methods

*['a','b'] * 2 # ['a','b','a','b'] Documentation Playground

['a','b'] * 2

["a", "b", "a", "b"]

pack[33,42,38].pack('CCC') # '!*&' Documentation Playground

[33,42,38].pack('CCC')

!*&

sum(number)[1,2,3].sum # 6 Documentation Playground

[1,2,3].sum(10)

16

Ruby class Array interactive

Creating

Methods

Creating an Array

Querying

Comparing

Fetching

Assigning

Deleting

Combining

Iterating

Converting

Other Methods