130 lines
		
	
	
		
			5.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			130 lines
		
	
	
		
			5.3 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
| ---
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| id: 587d8254367417b2b2512c6f
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| title: Perform a Subset Check on Two Sets of Data
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| challengeType: 1
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| videoUrl: ''
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| localeTitle: 对两组数据执行子集检查
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| ---
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| 
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| ## Description
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| <section id="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<code>Set</code>数据结构上创建一个名为<code>subset</code> 。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<code>setA = ['a','b']</code>和<code>setB = ['a','b','c','d']</code> ,则setA和setB的子集为: <code>setA.subset(setB)</code>应该是<code>true</code> 。 </section>
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| 
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| ## Instructions
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| <section id="instructions">
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| </section>
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| 
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| ## Tests
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| <section id='tests'>
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| 
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| ```yml
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| tests:
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|   - text: 你的<code>Set</code>类应该有一个<code>union</code>方法。
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|     testString: 'assert(function(){var test = new Set(); return (typeof test.subset === "function")}, "Your <code>Set</code> class should have a <code>union</code> method.");'
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|   - text: 第一个Set()包含在第二个Set中
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|     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");'
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|   - text: '<code>["a", "b"].subset(["a", "b", "c", "d"])</code>应该返回<code>true</code> “)'
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|     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)}, "<code>["a", "b"].subset(["a", "b", "c", "d"])</code> should return <code>true</code>");'
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|   - text: '<code>["a", "b", "c"].subset(["a", "b"])</code>应返回<code>false</code> “)'
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|     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)}, "<code>["a", "b", "c"].subset(["a", "b"])</code> should return <code>false</code>");'
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|   - text: '<code>[].subset([])</code>应该返回<code>true</code>'
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|     testString: 'assert(function(){var setA = new Set(); var setB = new Set(); var subsetSetAB = setA.subset(setB); return (subsetSetAB === true)}, "<code>[].subset([])</code> should return <code>true</code>");'
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|   - text: '<code>["a", "b"].subset(["c", "d"])</code>应返回<code>false</code> “)'
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|     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)}, "<code>["a", "b"].subset(["c", "d"])</code> should return <code>false</code>");'
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| 
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| ```
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| 
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| </section>
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| 
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| ## Challenge Seed
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| <section id='challengeSeed'>
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| 
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| <div id='js-seed'>
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| 
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| ```js
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| function Set() {
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|     // the var collection will hold the set
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|     var collection = [];
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|     // this method will check for the presence of an element and return true or false
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|     this.has = function(element) {
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|         return (collection.indexOf(element) !== -1);
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|     };
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|     // this method will return all the values in the set
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|     this.values = function() {
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|         return collection;
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|     };
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|     // this method will add an element to the set
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|     this.add = function(element) {
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|         if(!this.has(element)){
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|             collection.push(element);
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|             return true;
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|         }
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|         return false;
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|     };
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|     // this method will remove an element from a set
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|     this.remove = function(element) {
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|         if(this.has(element)){
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|            var index = collection.indexOf(element);
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|             collection.splice(index,1);
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|             return true;
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|         }
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|         return false;
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|     };
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|     // this method will return the size of the collection
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|     this.size = function() {
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|         return collection.length;
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|     };
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|     // this method will return the union of two sets
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|     this.union = function(otherSet) {
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|         var unionSet = new Set();
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|         var firstSet = this.values();
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|         var secondSet = otherSet.values();
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|         firstSet.forEach(function(e){
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|             unionSet.add(e);
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|         });
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|         secondSet.forEach(function(e){
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|             unionSet.add(e);
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|         });
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|         return unionSet;
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|     };
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|     // this method will return the intersection of two sets as a new set
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|     this.intersection = function(otherSet) {
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|         var intersectionSet = new Set();
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|         var firstSet = this.values();
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|         firstSet.forEach(function(e){
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|             if(otherSet.has(e)){
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|                 intersectionSet.add(e);
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|             }
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|         });
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|         return intersectionSet;
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|     };
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|     // this method will return the difference of two sets as a new set
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|     this.difference = function(otherSet) {
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|         var differenceSet = new Set();
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|         var firstSet = this.values();
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|         firstSet.forEach(function(e){
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|             if(!otherSet.has(e)){
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|                 differenceSet.add(e);
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|             }
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|         });
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|         return differenceSet;
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|     };
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|     // change code below this line
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|     // change code above this line
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| }
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| 
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| ```
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| 
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| </div>
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| 
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| 
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| 
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| </section>
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| 
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| ## Solution
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| <section id='solution'>
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| 
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| ```js
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| // solution required
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| ```
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| </section>
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