JavaScript is a language that must work in a particular environment, usually the environment for JavaScript is a web browser. Of course, the browser is not the only JavaScript environment. It can be e.g. node.js technology. But I'll tell you a little later.

The JavaScript philosophy on the internet is based on two models:

BOM (Browser Object Model) - for JavaScript

Browser Object Model - supports the behavior of external devices for the browser and the parent object for the browser JavaScript, i.e. the window object.

DOM (Document Object Model) - Document Object Model - for JavaScript

DOM is a standard managed and developed by the World Wide Web Consortium (W3C). It has several levels (0-3), which are implemented to different degrees by browsers.

In this part of the JavaScript training you will find information about the BOM, in the next - the DOM.

BOM Browser Object Model - The most important elements

Window - a JavaScript global object, all built-in JavaScript functions are methods of the window object.

Time for details - JavaScript BOM object

BOM - properties, methods:

NAVIGATOR - GOOD JavaScript

window.navigator - an object that provides knowledge about the browser and its capabilities

window.navigator.userAgent - identifies the browser

SCREEN - JavaScript BOM

The screen property contains information about the monitor settings, e.g. due to the property:

screen.colorDepth - you can read the color depth of the monitor

screen.width - you can read the width of the monitor

screen. .height - you can read the height of the monitor

screen.availWidth - you will read the available monitor width

screen.availHeight - you will read the available height of the monitor

window.close () - JavaScript closes a new window

window.moveTo (x, y) - JavaScript moves the browser window to position x, y

window.moveBy (x, y) - JavaScript moves the browser window to x, y

window.resizeTo (x, y) - JavaScript resizes the window by the parameters x, y

window.alert () - JavaScript opens a window with an alert - information for the user

window.prompt () - JavaScript opens a window with a field for entering text - gets text from the user

window.confirm () - JavaScript opens a window with the option for the user to choose between OK and Cancel

window.setTimeout () - JavaScript sets a function delay, example:

function watch out () {alert ('watch out for elephants?');}

setTimeout(uwazaj, 2000);

JavaScript - the above code will display 'watch out for elephants?' 2000 milliseconds delay (2 seconds)