如何动态地将地图添加到列表中？

Question

正如我在想映射添加到列表中动态，并避免添加地图使用相同的密钥我想这

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 

在真实的生活场景信问题描述将用户输入添加。

Answer 1

在这里你去：

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

您List和containsKey使用find在Map实例将完成你在找什么。 Maps的文档有更多信息。

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:[]]]