你想通过数组来交换变量。
使用 CoffeeScript 的解构赋值语法:
a = 1
b = 3
[a, b] = [b, a]
a
# => 3
b
# => 1
解构赋值可以不依赖临时变量实现变量值的交换。
这种语法特别适合在遍历数组的时候只想迭代最短数组的情况:
ray1 = [ 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 ]
ray2 = [ 5, 9, 14, 20 ]
intersection = (a, b) ->
[a, b] = [b, a] if a.length > b.length
value for value in a when value in b
intersection ray1, ray2
# => [ 5, 9 ]
intersection ray2, ray1
# => [ 5, 9 ]