実施例（第7回）

or (または ||) の意味

>irb
irb(main):001:0> nil || 'hello'
=> "hello"
irb(main):002:0> true || 'hello'
=> true
irb(main):003:0> nil or 'hello'
=> "hello"
irb(main):004:0> true or 'hello'
=> true

配列から最初の値を取り出す

irb(main):006:0> aaa=['hello','people']
=> ["hello", "people"]
irb(main):007:0> aaa.shift
=> "hello"
irb(main):008:0> aaa
=> ["people"]
irb(main):009:0> aaa.shift
=> "people"
irb(main):010:0> aaa
=> []
irb(main):011:0> aaa.shift
=> nil