返回Ruby哈希中成本小于$300的所有项

Question

我想返回任何便宜的，它应该返回任何价格低于300美元的物品。

这是主类;

class ShoesInventory
def initialize(items)
@items = items
end
def cheap
# this is my solution, but it just print out an array of boolean
@items.map { |item| item[:price] < 30 }
# to be implemented
end
end

这是类的一个实例;

ShoesInventory.new([
{price: 101.00, name: "Nike Air Force 1 Low"}},
{price: 232.00, name: "Jordan 4 Retro"},
{price: 230.99, name: "adidas Yeezy Boost 350 V2"},
{price: 728.00, name: "Nike Dunk Low"}
]).cheap

我希望结果是这样的;

# => [
#      {price: 101.00, name: "Nike Air Force 1 Low"}},
#      {price: 232.00, name: "Jordan 4 Retro"},
#      {price: 230.99, name: "adidas Yeezy Boost 350 V2"},
#    ]
Can you guide me ?

Answer 1

您要找的是Enumerable#select。

class ShoesInventory
def initialize(items)
@items = items
end
def cheap
@items.select { |item| item[:price] < 30 }
end
end

如果你希望能够链方法,您可能还想返回一个新的库存实例:

def cheap
self.class.new(@items.select { |item| item[:price] < 30 })
end