查找以“a”开头的字符串中的单词数

Question

在Ruby中，我希望显示此字符串中以“a”开头的单词数：an ant hello hint how are you

Answer 1

您可以将正则表达式与扫描结合使用

string.scan(/\ba/).size

Answer 2

"a asa  a ss sa a a a ass a ".split.select {|w| w[0] == "a"}.size

Answer 3

p "an ant hello hint how are you".split.count{|word| word.start_with?('a')}
#=> 3