搜索数组中的特定项

Question

我想搜索数组：

letters = ["a", "b", "c", "d", "e"]

查看"b"是否在其中;如果是，那么应该说是。我明白了：

letters[0..0] == ["a"]

我试过了：

if letters[0..5] == ["b"]
  puts "Yes, the letter 'b' in there."
else
  puts "No 'b' in the array."
end

Answer 1

有一种内置方法可以做到这一点：

letters.include? "b"

Answer 2

尝试：http://www.ruby-doc.org/core-2.1.3/Array.html#method-i-include-3F

if letters.include?("b")
  puts "Yes, the letter 'b' in there."
else
  puts "No 'b' in the array."
end

Answer 3

if letters.index('b')
    puts "yes"
else
    puts "no"
end