在 Groovy 中添加两个映射，同时汇总公共键的值 [英] Add two maps in Groovy while summing up values for common keys

问题描述

我在 Groovy [a: 1, b: 2] 和 [b:1, c:3] 中有两个映射，我想用它们创建一个第三张地图[a: 1, b: 3, c: 3].是否有执行此操作的 Groovy 命令?

I have two maps in Groovy [a: 1, b: 2] and [b:1, c:3] and would like to create from them a third map [a: 1, b: 3, c: 3]. Is there a Groovy command that does that?

编辑:请注意，如果键相同，则第三个映射中的值是前两个映射中值的总和.

Edit: Notice that the values in the third map, are a sum of the values from the first two maps, if the keys are identical.

谢谢

推荐答案

另一种解决方案是:

def m1 = [ a:1, b:2 ]
def m2 = [ b:1, c:3 ]

def newMap = [m1,m2]*.keySet().flatten().unique().collectEntries {
  [ (it): [m1,m2]*.get( it ).findAll().sum() ]
}

以epidemian's answer为灵感，你也可以写一个方法来处理多张地图

Taking epidemian's answer as inspiriation, you can also write a method to handle multiple maps

def m1 = [a: 1, b: 2]
def m2 = [b: 1, c: 3]

def combine( Map... m ) {
  m.collectMany { it.entrySet() }.inject( [:] ) { result, e ->
    result << [ (e.key):e.value + ( result[ e.key ] ?: 0 ) ]
  }
}

def newMap = combine( m1, m2 )

这篇关于在 Groovy 中添加两个映射，同时汇总公共键的值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！