The Window Object#

The window acts as a global variable, representing the window in which the script is running, and exposes properties and methods to JavaScript.

Properties of the Window Object#

• closed: Indicates whether the referenced window is closed.
• console: Provides methods to output log information to the browser console.
• crypto: This object allows web pages to access certain encryption-related services.
• customElements: Can be used to register new custom elements or retrieve information about previously defined custom elements.
• devicePixelRatio: Returns the ratio of the physical pixel resolution of the current display device to the CSS pixel resolution.
• document: Returns a reference to the document object.
• frameElement: Returns the element embedded in the current window object, such as <iframe> or <object>, and returns null if the current window object is already the top-level window.
• frames: Returns an array-like object that lists all the direct child windows of the current window.
• fullScreen: Indicates whether the window is in full-screen mode.
• history: Provides an interface for manipulating the browser session history.
• indexedDB: Integrates mechanisms to provide asynchronous access to indexed databases for applications.
• innerHeight: Returns the height of the document display area of the window.
• innerWidth: Returns the width of the document display area of the window.
• length: Sets or returns the number of <iframe> frames in the window.
• localStorage: Provides a long-term local storage interface.
• location: Contains information about the current document location.
• locationbar: Returns a locationbar object with a visibility property that can be checked.
• name: Sets or returns the name of the window.
• navigator: Provides information related to the application running the current code.
• opener: Returns a reference to the window that opened this window.
• outerHeight: Returns the outer height of the window, including the toolbar and scrollbar.
• outerWidth: Returns the outer width of the window, including the toolbar and scrollbar.
• pageXOffset: Sets or returns the X position of the current page relative to the upper left corner of the window display area.
• pageYOffset: Sets or returns the Y position of the current page relative to the upper left corner of the window display area.
• parent: Returns the parent window object of the current window, or returns a self-reference if there is no parent window.
• performance: Allows web pages to access certain functions to measure the performance of web pages and web applications.
• screen: Returns properties related to the current rendering window and screen.
• screenLeft: Returns the X coordinate relative to the screen window.
• screenTop: Returns the Y coordinate relative to the screen window.
• screenX: Returns the X coordinate relative to the screen window.
• screenY: Returns the Y coordinate relative to the screen window.
• sessionStorage: Provides a local storage interface with current session validity.
• self: Returns a reference to the current window.
• status: Sets the text of the window status bar.
• top: Returns a reference to the topmost window in the window hierarchy.

Methods of the Window Object#

• alert(): Displays an alert dialog with specified text content and an OK button.
• atob(): Decodes a string encoded with Base64.
• btoa(): Creates a Base64 encoded string.
• blur(): Moves the keyboard focus away from the top-level window.
• clearInterval(): Cancels the interval set by setInterval().
• clearTimeout(): Cancels the timeout set by the setTimeout() method.
• close(): Closes the current window or a specified window.
• confirm(): Displays a dialog with a message, an OK button, and a Cancel button.
• focus(): Gives focus to a window.
• getComputedStyle(): Gets the CSS styles of a specified element.
• matchMedia(): Returns the result object of a specified media query string parsing.
• moveBy(): Moves the window created by open by a specified amount.
• moveTo(): Moves the top-left corner of the window created by open to a specified coordinate.
• open(): Opens a new browser window or finds a named window.
• postMessage(): Safely implements cross-origin communication.
• print(): Prints the content of the current window.
• prompt(): Displays a dialog prompting the user for input.
• requestAnimationFrame(): Provides a method for drawing animation frames to match the screen refresh rate.
• queueMicrotask(): Provides a callback interface for adding to the microtask queue.
• resizeBy(): Adjusts the size of the window created by open by a specified number of pixels.
• resizeTo(): Adjusts the size of the window created by open to a specified width and height.
• scroll(): Scrolls the window to a specific position in the document.
• scrollBy(): Scrolls the document within the window by a specified offset.
• scrollTo(): Scrolls the content to the specified coordinates.
• setInterval(): Calls a function or evaluates an expression at specified intervals.
• setTimeout(): Calls a function or evaluates an expression after a specified number of milliseconds.
• stop(): Stops the loading of the page, equivalent to clicking the stop button in the browser.

Events of the Window Object#

Load-related#

• onbeforeunload: Occurs just before the document is about to be unloaded (refreshed or closed).
• onload: Occurs when the document has finished loading.
• onunload: Occurs when the window unloads its resources and content.
• onerror: Occurs when a JavaScript runtime error or resource loading failure happens.
• onabort: Event handler for the abort event sent to the window, not applicable to Firefox 2 or Safari.

Window-related#

• onblur: Occurs when the window loses focus.
• onfocus: Occurs when the window gains focus.
• onresize: Occurs when the window size changes.
• onscroll: Occurs when the window scrolls.
• onmessage: Occurs when the window object receives a message.
• onchange: Occurs when the content of a form element in the window changes.
• oninput: Occurs when a form element in the window gets user input.
• onreset: Occurs when a form in the window is reset.
• onselect: Occurs when text in a form element in the window is selected.
• onsubmit: Occurs when the submit button in a form in the window is pressed.
• onhashchange: Occurs when the anchor/hash value of the window changes.

Mouse Related#

• onclick: Triggered when the page is clicked.
• onmouseup: Triggered when the mouse button is released.
• ondblclick: Called when the page is double-clicked.
• oncontextmenu: Triggered when the right mouse button is clicked to open the context menu.
• onmousedown: Triggered when the mouse button is pressed.
• onmousemove: Triggered when the mouse is moved.
• onmouseout: Triggered when the mouse moves out of the window.
• onmouseover: Triggered when the mouse moves over the window.
• onauxclick: Indicates that a non-primary button is pressed on an input device, such as the middle button of a mouse.

Keyboard Related#

• onkeydown: Triggered when a keyboard key is pressed.
• onkeyup: Triggered when a keyboard key is released.
• onkeypress: Triggered when a keyboard key is pressed and then released.

Animation Related#

• onanimationcancel: Sent when a CSS animation is unexpectedly terminated, i.e., at any time it stops running without sending an animationend event, for example, when animation-name is changed or the animation is deleted.
• onanimationend: Sent when a CSS animation reaches the end of its active period, calculated as (animation-duration*animation-iteration-count) + animation-delay.
• onanimationiteration: Triggered when a CSS animation completes one iteration of the sequence of animation instructions by executing the last step of the animation.

Device Related#

• ondevicemotion: Triggered when the device's state changes.
• ondeviceorientation: Triggered when the device's relative orientation changes.
• ondeviceproximity: Triggered when the device's sensor detects an object getting closer to or further away from the device.

Print Related#

• onbeforeprint: Triggered when the page is about to start printing.
• onafterprint: Triggered when the page has started printing or the print window has been closed.

Application Related#

• onappinstalled: Dispatched once a Web application is successfully installed as a progressive Web application.

• onbeforeinstallprompt: Scheduled on the device when the user is about to be prompted to install a web application, and its associated events can be saved for later use in prompting the user at a more opportune time.

Daily Question#

Reference#