array = [1, 3, 5, 7, 9]
p array.bsearch {|n| n > 6 }
p array.bsearch {|n| n > 10}
7 nil
p array.bsearch {|n| n < 4 }
nil
array = [24, 1, 365]
p array.join
array.join('-')
"241365"
"24-1-365"
# Python
#'-'.join(list)
array*'-'
"24-1-365"
array * 3
[24, 1, 365, 24, 1, 365, 24, 1, 365]
array = [1, 2]
p array.hash
array.reverse!
array.hash
656715179053826656
2020695210800531113
:foo.hash
9605
:foo.hash
9605
p 'foo'.hash
'foo'.hash
-1214599741921765595
-1214599741921765595
hash = {one: 1, two: 2}
hash.each do |k, v|
puts "#{k}: #{v}"
end
hash.each_key do |k|
puts k
end
hash.each_value do |v|
puts v
end
one: 1 two: 2 one two 1 2
{:one=>1, :two=>2}
hash = {}
hash[:foo] = 'bar'
hash
{:foo=>"bar"}
hash = {foo: 'bar'}
hash.delete(:foo)
hash
{}
hash = {foo: 1, bar: 2, buzz: 3}
hash.select! {|k,v| v.odd?}
p hash
hash = {foo: 1, bar: 2, buzz: 3}
hash.reject!{|k, v| v.odd?}
hash
{:foo=>1, :buzz=>3}
{:bar=>2}
hash = {foo: 1, bar: 2, buzz: 3}
p hash.keep_if {|k, v| true}
hash.delete_if {|k, v| false}
{:foo=>1, :bar=>2, :buzz=>3} {:foo=>1, :bar=>2, :buzz=>3}
{:foo=>1, :bar=>2, :buzz=>3}
hash = {foo: 1, bar: 2, buzz: 3}
p hash.select! {|k, v| true}
hash = {foo: 1, bar: 2, buzz: 3}
p hash.reject! {|k, v| false}
nil nil
hash = {foo: 1, bar: 2, buzz: 3}
p hash.select {|k,v| v.odd?}
p hash.reject {|k,v| v.odd?}
hash
{:foo=>1, :buzz=>3} {:bar=>2}
{:foo=>1, :bar=>2, :buzz=>3}
次回は5-5-3Hash ■マージから
names = {a: 'alice', b: 'bob', c: 'chalie'}
names.transform_values {|name| name.capitalize}
{:a=>"Alice", :b=>"Bob", :c=>"Chalie"}
names = {a: 'alice', b: 'bob', c: nil}
names.compact
NoMethodError: undefined method `compact' for {:a=>"alice", :b=>"bob", :c=>nil}:Hash (pry):95:in `<main>' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:355:in `eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:355:in `evaluate_ruby' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:323:in `handle_line' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:243:in `block (2 levels) in eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:242:in `catch' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:242:in `block in eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:241:in `catch' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/pry-0.10.4/lib/pry/pry_instance.rb:241:in `eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/backend.rb:65:in `eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/backend.rb:12:in `eval' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/kernel.rb:87:in `execute_request' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/kernel.rb:47:in `dispatch' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/kernel.rb:37:in `run' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/command.rb:70:in `run_kernel' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/lib/iruby/command.rb:34:in `run' /Users/ariga/.rbenv/versions/2.4.0-preview2/lib/ruby/gems/2.4.0/gems/iruby-0.2.9/bin/iruby:5:in `<top (required)>' /Users/ariga/.rbenv/versions/2.4.0-preview2/bin/iruby:22:in `load' /Users/ariga/.rbenv/versions/2.4.0-preview2/bin/iruby:22:in `<main>'