freeCodeCamp/curriculum/challenges/english/08-coding-interview-prep/data-structures/remove-from-a-set.english.md

id	title	challengeType
587d8253367417b2b2512c6b	Remove from a Set	1

Description

In this exercises we are going to create a delete function for our set. The function should be named this.remove. 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.

Instructions

Tests

tests:
  - text: Your <code>Set</code> class should have a <code>remove</code> method.
    testString: assert((function(){var test = new Set(); return (typeof test.remove === 'function')}()), 'Your <code>Set</code> class should have a <code>remove</code> method.');
  - text: Your <code>remove</code> method should only remove items that are present in the set.
    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.');
  - text: Your <code>remove</code> method should remove the given item from the set.
    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.');

Challenge Seed

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;
    };
    // change code below this line
    // change code above this line
}

Solution

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;};}