---
id: 587d8254367417b2b2512c6f
title: Perform a Subset Check on Two Sets of Data
challengeType: 1
videoUrl: ''
localeTitle: 对两组数据执行子集检查
---
## Description
在本练习中，我们将对2组数据执行子集测试。我们将在我们的Set数据结构上创建一个名为subset 。这将比较第一组与第二组，如果第一组完全包含在第二组中，则它将返回true。例如，如果setA = ['a','b']和setB = ['a','b','c','d'] ，则setA和setB的子集为： setA.subset(setB)应该是true 。
## Instructions
## Tests
```yml
tests:
- text: 你的Set类应该有一个union方法。
testString: 'assert(function(){var test = new Set(); return (typeof test.subset === "function")}, "Your Set class should have a union method.");'
- text: 第一个Set（）包含在第二个Set中
testString: 'assert(function(){var setA = new Set(); var setB = new Set(); setA.add("a"); setB.add("b"); setB.add("c"); setB.add("a"); setB.add("d"); var subsetSetAB = setA.subset(setB);return (subsetSetAB === true)}, "The first Set() was contained in the second Set");'
- text: '["a", "b"].subset(["a", "b", "c", "d"])应该返回true “）'
testString: 'assert(function(){var setA = new Set(); var setB = new Set(); setA.add("a"); setA.add("b"); setB.add("a"); setB.add("b"); setB.add("c"); setB.add("d"); var subsetSetAB = setA.subset(setB); return (subsetSetAB === true)}, "["a", "b"].subset(["a", "b", "c", "d"]) should return true");'
- text: '["a", "b", "c"].subset(["a", "b"])应返回false “）'
testString: 'assert(function(){var setA = new Set(); var setB = new Set(); setA.add("a"); setA.add("b"); setA.add("c"); setB.add("a"); setB.add("b"); var subsetSetAB = setA.subset(setB); return (subsetSetAB === false)}, "["a", "b", "c"].subset(["a", "b"]) should return false");'
- text: '[].subset([])应该返回true'
testString: 'assert(function(){var setA = new Set(); var setB = new Set(); var subsetSetAB = setA.subset(setB); return (subsetSetAB === true)}, "[].subset([]) should return true");'
- text: '["a", "b"].subset(["c", "d"])应返回false “）'
testString: 'assert(function(){var setA = new Set(); var setB = new Set(); setA.add("a"); setA.add("b"); setB.add("c"); setB.add("d"); var subsetSetAB = setA.subset(setB); return (subsetSetAB === false)}, "["a", "b"].subset(["c", "d"]) should return false");'
```
## Challenge Seed
```js
function Set() {
// the var collection will hold the set
var collection = [];
// this method will check for the presence of an element and return true or false
this.has = function(element) {
return (collection.indexOf(element) !== -1);
};
// this method will return all the values in the set
this.values = function() {
return collection;
};
// this method will add an element to the set
this.add = function(element) {
if(!this.has(element)){
collection.push(element);
return true;
}
return false;
};
// this method will remove an element from a set
this.remove = function(element) {
if(this.has(element)){
var index = collection.indexOf(element);
collection.splice(index,1);
return true;
}
return false;
};
// this method will return the size of the collection
this.size = function() {
return collection.length;
};
// this method will return the union of two sets
this.union = function(otherSet) {
var unionSet = new Set();
var firstSet = this.values();
var secondSet = otherSet.values();
firstSet.forEach(function(e){
unionSet.add(e);
});
secondSet.forEach(function(e){
unionSet.add(e);
});
return unionSet;
};
// this method will return the intersection of two sets as a new set
this.intersection = function(otherSet) {
var intersectionSet = new Set();
var firstSet = this.values();
firstSet.forEach(function(e){
if(otherSet.has(e)){
intersectionSet.add(e);
}
});
return intersectionSet;
};
// this method will return the difference of two sets as a new set
this.difference = function(otherSet) {
var differenceSet = new Set();
var firstSet = this.values();
firstSet.forEach(function(e){
if(!otherSet.has(e)){
differenceSet.add(e);
}
});
return differenceSet;
};
// change code below this line
// change code above this line
}
```
## Solution
```js
// solution required
```