SOURCE

'use strict';

Array.prototype.first = function() {
	return this[0];
};

Array.prototype.last = function() {
	return this[this.length - 1];
};

Array.prototype.removeAtIndex = function(index) {
	if (isNaN(index) || index > this.length) {
		return false;
	}
	this.splice(index, 1);
	return true;
};

Array.prototype.removeObj = function(value) {
	let index = this.indexOf(value);
	if (!index) return false;
	this.splice(index, 1);
	return true;
};