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A string in JavaScript is an immutable object that contains none, one or many characters.
A string can be defined using single or double quotes.
A string in JavaScript has some built-in methods to manipulate the string.
All strings have a length property.
An empty string defaults to false.
Numbers in JavaScript are double-precision 64-bit format IEEE 754 values.
If a number is zero, it defaults to false.
JavaScript provides utilities to work with numbers in the Math object.
parseInt and parseFloat help parsing strings into numbers.
When appending numbers to string, the result is always a string.
Parsing something that isn't a number results in NaN.
An integer is a plain Number type.
A float is a plain Number type.
A boolean in JavaScript can be either true or false.
Everything in JavaScript is an object.
You can write and read properties of an object using the dot notation.
Or you write and read properties using the array notation, which allows you to dynamically choose the property.
Iterating over objects is easy with the for-in-loop.
An object, no matter if it has properties or not, never defaults to false.
All objects have a prototype property.
Options in jQuery are plain JavaScript objects.
Arrays in JavaScript are mutable lists with a few built-in methods.
An array has a length property that is useful for iteration.
An array, no matter if it has elements or not, never defaults to false.
In the jQuery API you'll often find the notation of Array<Type>.
The map type is used by the AJAX function to hold the data of a request.
A function in JavaScript can be either named or anonymous.
Inside a function a special variable "arguments" is always available.
In JavaScript, the variable "this" always refers to the current context.
In JavaScript, all variables defined inside a function are only visible inside that function scope.
Closures are created whenever a variable that is defined outside the current scope is accessed from within some inner scope.
Combining the above knowledge gives you as a JavaScript developer quite a lot of power.
A callback is a plain JavaScript function passed to some method as an argument or option.
A selector is used in jQuery to select DOM elements from a DOM document.
jQuery's event system normalizes the event object according to W3C standards.
An element in the Document Object Model (DOM) has attributes, text and children.
A jQuery object contains a collection of Document Object Model (DOM) elements that have been created from an HTML string or selected from a document.
Internet media type.
XMLHttpRequest (XHR) is a DOM API that can be used inside a web browser scripting language
Deferred object provides a way to register multiple callbacks into self-managed callback queues
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