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Ruby | Array | push,pop,delete,shift,unshift,insert,delete_at

概要

Array#push,pop,delete,shift,unshift,insert,delete_at

詳細

配列の1つの要素に対する追加、削除操作一覧。

method add/remove description
push add 末尾に引数で指定した要素を追加
pop remove 末尾を削除
delete remove 引数で指定した要素を削除
unshift add 先頭に引数で指定した要素を追加
shift remove 先頭を削除
insert add 引数で指定したindexに引数で指定した要素を追加
delete_at remove 引数で指定したindexの要素を削除

サンプルコード

# encoding: utf-8
require "erb"

def println(value)
  print "#{value}\n"
end

ary = [1,2,3]
println "start=#{ary}"
ary.push 4
println "after push 4 =  #{ary}"
ary.pop
println "after pop =  #{ary}"
ary.shift
println "after shift =  #{ary}"
println "after unshift 5 =  #{ary.unshift 5}"
println "after insert(1, 6) =  #{ary.insert(1, 6)}"
ary.delete 2
println "after delete 2 =  #{ary}"
ary.delete_at 2
println "after delete_at 2 =  #{ary}"

出力

start=[1, 2, 3]
after push 4 =  [1, 2, 3, 4]
after pop =  [1, 2, 3]
after shift =  [2, 3]
after unshift 5 =  [5, 2, 3]
after insert(1, 6) =  [5, 6, 2, 3]
after delete 2 =  [5, 6, 3]
after delete_at 2 =  [5, 6]