如何测试一个数组是否是另一个数组的子集？

What's the best (cleanest) way to provide this sort of logic?

提供这种逻辑的最好(最干净)方法是什么?

var colors = ["red","white","blue"];

logic(colors,["red","green"]); //false
logic(colors,["red"]); //true
logic(colors,["red","purple"]); //false
logic(colors,["red","white"]); //true
logic(colors,["red","white","blue"]); //true
logic(colors,["red","white","blue","green"]); //false
logic(colors,["orange"]); //false

Possibly using underscore.js?

可能使用underscore.js?

2 个解决方案

#1

Assuming each element in the array is unique: Compare the length of hand with the length of the intersection of both arrays. If they are the same, all elements in hand are also in colors.

假设数组中的每个元素都是唯一的:将hand的长度与两个数组的交集长度进行比较。如果它们相同,则手中的所有元素也都是颜色。

var result = (hand.length === _.intersection(hand, colors).length);

DEMO

#2

Maybe difference is what you are looking for:

也许差异就是你要找的东西:

_(hand).difference(colors).length === 0

#1