Using the prototype makes faster object creation since properties/methods on the prototype don’t have to be re-created each time a new object is created. When you do this: function animal() { this.name=”rover” this.set_name = function (name) { this.name = name } } The set_name method is created every time you create an animal. But when … Read more
For preserving the context, the bind method is really useful, it’s now part of the recently released ECMAScript 5th Edition Specification, the implementation of this function is simple (only 8 lines long): // The .bind method from Prototype.js if (!Function.prototype.bind) { // check if native implementation available Function.prototype.bind = function(){ var fn = this, args … Read more
I’ve been trying to wrap my head around this recently and finally came up with this “map” that I think sheds full light over the matter http://i.stack.imgur.com/KFzI3.png I know I’m not the first one making this up but it was more interesting figuring it out that finding it :-). Anyway, after that I found e.g. … Read more
Use reduce with destructuring to sum Amount: const traveler = [ { description: ‘Senior’, Amount: 50 }, { description: ‘Senior’, Amount: 50 }, { description: ‘Adult’, Amount: 75 }, { description: ‘Child’, Amount: 35 }, { description: ‘Infant’, Amount: 25 }, ]; console.log(traveler.reduce((n, {Amount}) => n + Amount, 0))