78 lines
2.7 KiB
Markdown
78 lines
2.7 KiB
Markdown
---
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id: 587d8253367417b2b2512c6b
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title: Remove from a Set
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challengeType: 1
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---
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## Description
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<section id='description'>
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In this exercises we are going to create a delete function for our set. The function should be named <code>this.remove</code>. This function should accept a value and check if it exists in the set. If it does, remove that value from the set, and return true. Otherwise, return false.
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</section>
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## Instructions
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<section id='instructions'>
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</section>
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## Tests
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<section id='tests'>
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```yml
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tests:
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- text: Your <code>Set</code> class should have a <code>remove</code> method.
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testString: assert((function(){var test = new Set(); return (typeof test.remove === 'function')}()), 'Your <code>Set</code> class should have a <code>remove</code> method.');
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- text: Your <code>remove</code> method should only remove items that are present in the set.
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testString: assert.deepEqual((function(){var test = new Set(); test.add('a');test.add('b');test.remove('c'); return test.values(); })(), ['a', 'b'], 'Your <code>remove</code> method should only remove items that are present in the set.');
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- text: Your <code>remove</code> method should remove the given item from the set.
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testString: assert((function(){var test = new Set(); test.add('a');test.add('b');test.remove('a'); var vals = test.values(); return (vals[0] === 'b' && vals.length === 1)}()), 'Your <code>remove</code> method should remove the given item from the set.');
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```
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</section>
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## Challenge Seed
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<section id='challengeSeed'>
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<div id='js-seed'>
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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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// 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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</div>
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</section>
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## Solution
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<section id='solution'>
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```js
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function Set() {var collection = []; this.has = function(e){return(collection.indexOf(e) !== -1);};this.values = function() {return collection;};this.add = function(element) {if (!this.has(element)) {collection.push(element);return true;} else {return false;}};this.remove = function(element) {if(this.has(element)) {var i = collection.indexOf(element);collection.splice(i, 1);return true;}return false;};}
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```
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</section>
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