Array.prototype.reject(): TypeError: ....reject is not a function
<p>I am taking a cool online course about functional programming in JavaScript. I was following along just fine until the instructor used the <code>Array.prototype.reject()</code> and it did not work for me at run time.</p>

<p>I would like to use "reject" instead of a for loop because it is less code. But, my browser, NodeJS and Express Code consoles tell me that <code>reject is not a function</code>.</p>

<p>I researched other articles that discuss <code>promise.reject</code> is not a function, but provide solutions that do not make sense to my scenario. </p>

<p>Here is the example code in the course:</p>

<pre><code>var animals = [
    { name: 'Fluffykins',   species: 'rabbit' },
    { name: 'Caro',         species: 'dog' },
    { name: 'Hamilton',     species: 'dog' },
    { name: 'Harold',       species: 'fish' },
    { name: 'Ursula',       species: 'cat' },
    { name: 'Jimmy',        species: 'fish' }
];


var isDog = function(animal){
    return animal.species === 'dog';
}

var otherAnimals = animals.reject(isDog);
</code></pre>

<p>The work-around with a for-loop:</p>

<pre><code>var notDogs = animals.filter(function(animal){
    return animal.species !== 'dog';
});
</code></pre>

<p>Its output is:</p>

<pre><code>&gt; notDogs
[ { name: 'Fluffykins', species: 'rabbit' },
  { name: 'Harold', species: 'fish' },
  { name: 'Ursula', species: 'cat' },
  { name: 'Jimmy', species: 'fish' } ]
</code></pre>

<p>Please help me use <a href="https://github.com/thejameskyle/Array.prototype.reject" rel="noreferrer">Array.prototype.reject()</a>.</p>

<p>EditL</p>

<p>I found Array.prototype.reject() at <a href="https://github.com/thejameskyle" rel="noreferrer">GitHub</a>/Array.prototype.reject)</p>