Question

正如我在问题中描述的那样，我想动态地将地图添加到列表中，并避免使用相同的键添加地图我正在尝试这个

def myList = []
["a", "b", "c", "c", "d", "e", "f", "a" ,"f"].each { letter ->
   def map = [:]

   //here I want to check if current letter exist as key in myList
   //if it is true then avoid next code

   map.put(letter, [])
   myList << map
}

println myList

在现实生活场景中，字母将是用户添加的输入。

Answer 1

你走了：

def myList = []

["a", "b", "c", "c", "d", "e", "f", "a" ,"f"].each { letter ->  
   if(!myList.find { it.keySet().contains(letter) })
      myList << [(letter): []]
}
assert myList ==  [[a:[]], [b:[]], [c:[]], [d:[]], [e:[]], [f:[]]]

或者你可以简单地说：

def myList = ["a", "b", "c", "c", "d", "e", "f", "a" ,"f"].unique().collect { [(it):[]] }
assert myList ==  [[a:[]], [b:[]], [c:[]], [d:[]], [e:[]], [f:[]]]

Answer 2

使用find上的List和containsKey实例上的Map即可完成您的目标。 Maps的文档提供了更多信息。

def myList = []

["a", "b", "c", "c", "d", "e", "f", "a" ,"f"].each { letter ->
  def map = [:]
  if (!myList.find{ it.containsKey(letter) }) {
    map.put(letter, [])
    myList << map
  }
}

println myList // [[a:[]], [b:[]], [c:[]], [d:[]], [e:[]], [f:[]]]

如何动态地将地图添加到列表？

2 个答案: