数组
数组的简单使用
arr = [1, 3, 3.14, "饥人谷", true]
p arr[0] # => 1
p arr[-1] # => true
p arr.length # => 5
p arr.size # => 5
arr[8] = "若愚"
p arr # => [1, 3, 3.14, "饥人谷", true, nil, nil, nil, "若愚"]
数组循环
arr = [1, 3, 5, 6]
arr.each do |value|
p value + value
end
do 和 end 间的代码叫做块，也可用 {}代替do和end，一般多行用do ... end ，单行用 {}
arr.each { |value| p value + value }
散列
简单使用
school = {"name" => "jirengu", "age" => 3}
p school["name"] # => "jirengu"
# p school.age 错误写法
散列由 key 和 value 构成，中间用=>连接
people = {:name => "ruoyu", :sex => "male"}
p people[:name] # => "ruoyu"
key 可以是字符串可以是数字，也可以是符号，如 :name。对于key 为符号的散列，可以把:写到后面。上面的写法和下面是等价的。
friend = {name: "fangfang", sex: "male"}
p people[:name] # => "fangfang"
散列的遍历
friend = {name: "fangfang", sex: "male"}
friend.each do |key, value|
p "#{key} : #{value}"
end
正则表达式
puts /el/ =~ "hello" # => 1
puts /abc/ =~ "hello" # => nil
使用 =~来进行匹配， 如果匹配上得到匹配的下标，如果匹配不上得到nil
words = ["小明", "小刚", "小花", "大鱼"]
select_word = []
words.each do |word|
if(/小/=~ word)
select_word << word # 向数组添加元素
end
end
p select_word # => ["小明", "小刚", "小花"]
