JavaScript Window Object | window.open, close, print

Window

JS Window Object is the global object in JavaScript. For a web browser, window object tell information about current browser window. Window Object is also the global object of browser environment.

window object is available in browser environment only. In other environment's, there is no window object. For exp, in Node JS, global is used instead of window object.

We can also use globalThis, a common object in modern JS for both frontend and backend.

All global variables and functions are windows properties and methods. See Example


    var x="hello js";
    var y=function(){ return "hi"};
    
    window.x;          // return "hello js"
    window.y();        // return "hi"

But Block scope const and let are not windows properties and methods.


    let x="hello js";
    let y=function(){ return "hi"};
    const pi=Math.PI;
    
    
    window.x;            // return undefined
    window.y;            // return window.y is not a function 
    window.pi            // return undefined

Window Properties

Some common properties of Window Object.

Window Properties
Property	Details	Use
innerWidth	width of window
innerHeight	height of window
devicePixelRatio	ratio of physical resolution by actual resolution

Window Methods

JS Window Methods or build in functions.

Window Methods
Method	Use
window.open()	Open a new browser window. For exp `window.open("print.html","_blank","width=400,height=500,top=100,left=300,resizable=yes")`
window.close()	Close browser window opened by window.open method. For exp `window.close()`
window.print()	Print current browser window. Exp `window.print()`
window.resizeTo()	resize browser to parameter inside. For exp `window.resizeTo(600,400)` will resize window to 600 by 400.
window.moveTo	move window to left top corner of screen

Get all window Properties and methods

To get all windows properties and methods for current browser, we can use for in loop on window object. Most of the properties of windows objects are same on all browsers, but some may not exists on another browser. The reason is different browser engine.


for( let i in window){
    console.log(i, window[i]);
}

Output of loop in table

S No	Property	Value