Lesson 3: Understanding Data in JavaScript, Downloadable VersionJeff Tapper
Can you talk about your understanding ofthis? The direction ofthisis not determined at the time of wraiting, but determined at the time of execution. At the same time, the different direction of this lies in following certain rules. First of all, by default, thethisrefers to the object o...
In this tutorial, we learned the difference between properties and methods, how to create objects, and how to add, remove, modify, and loop through object properties. To learn more about JavaScript objects, read aboutWorking with Objectson the Mozilla Developer Network. Thanks for learning with ...
In this two-part article, I will explain the JavaScript prototype chain,JavaScript closures and the scope chainso that you can understand how to debug specific issues and how to use them to your advantage. JavaScript: a Despised Programming Language It can be said thatJavascript is one of the...
The this keyword is a very important concept in JavaScript, and also a particularly confusing one to both new developers and those who have experience in o…
Compared to other languages, JavaScript’s concept of undefined is a little confusing. In particular, trying to understand ReferenceErrors (“x is not defined”) and how best to code against them can be frustrating. This is my attempt to straighten things out a little. If you’re not alread...
In JavaScript, objects are pairs of keys and values (in Ruby, this structure is called a Hash; in Python, it’s called a dictionary). For example, if I wanted to describe my name, I could have an object with two keys: `firstName` would point to “Yehuda” and `lastName` would po...
snameinstance property as well as thespeakprototype property. This is where the prototype chain comes in – when we requestcat.name, JavaScript finds thenameinstance property and doesn’t bother going down the prototype chain. However when we requestcat.speak, JavaScript has to travel down the ...
The next very common way to invoke a method is as a member of an object (person.hello()). In this case, the invocation desugars: varperson = { name:"Brendan Eich", hello:function(thing) { console.log(this+" says hello "+ thing); ...
If you understand the basic rules for converting a sugary function call into a desugaredfunc.call(thisValue, ...args), you should be able to navigate the not so treacherous waters of the JavaScriptthisvalue. PS: I Cheated In several places, I simplified the reality a bit from the exact ...