Recreating the lodash pull() method with vanilla JS

Just for fun, I started looking at methods in lodash and creating vanilla JS equivalents.

Today, we’re going to recreate the lodash _.pull() method with vanilla JS.

What it does

The _.pull() method takes an array, and removes any values that match what you pass in.

var array = ['a', 'b', 'c', 'a', 'b', 'c'];
_.pull(array, 'a', 'c');

// logs ['b', 'b']
console.log(array);

First, let’s create a pull() helper method. Unlike the lodash version, we’ll pass in an array for values.

var pull = function (array, values) {
	// Do stuff...
};

Next, we’ll call the Array.filter() method on the array that’s passed in.

var pull = function (arr, values) {
	return arr.filter(function (item) {
		// Do stuff...
	});
};

Finally, we’ll check if the current item is in the array of values to remove using the Array.indexOf() method.

If the method is greater than 0, we’ll return a falsy value. Otherwise, we’ll return truthy.

var pull = function (arr, values) {
	return arr.filter(function (item) {
		return values.indexOf(item) < 0;
	});
};

Unlike the lodash version, this returns a new immutable array, so we’ll need to assign it to a variable.

Now we can do this.

var array = ['a', 'b', 'c', 'a', 'b', 'c'];
var pulled = pull(array, ['a', 'c']);

// logs ['b', 'b']
console.log(pulled);