从一系列哈希中获取数据

Question

给出以下哈希数组：

[{name: "joe", age: 21}, {name: "mary", age: 32}, {name: "mark", age: 25}]

如何获取返回的名称数组，如下所示：

["joe","mary","mark"]

Answer 1

使用#map

arr = [{name: "joe", age: 21}, {name: "mary", age: 32}, {name: "mark", age: 25}]
arr.map { |x| x[:name] }
# => ["joe", "mary", "mark"] 

Answer 2

只需使用Array#collect方法

即可

ary_of_hash = [{name: "joe", age: 21}, {name: "mary", age: 32}, {name: "mark", age: 25}]
ary_of_hash.collect { |hash| hash[:name] }

Answer 3

我认为地图解决了这个问题。

[{name: "joe", age: 21}, {name: "mary", age: 32}, {name: "mark", age: 25}].map(function(node){return node.name});

// returns ["joe", "mary", "mark"]

.map()

的

Reference and fallback