Overview of event object properties

Introduction

Whenever an event occurs (eng. event), javascript places all relevant data related to the event in an “event object”, e.g. where was the mouse pointer, which button was clicked, which element was clicked… This object is always passed to the callback function, and therefore the callback function has access to all the data stored in it. We access the data through the property of the event object. All properties of the Event object are gathered in this article.

Main properties of the event object

Object property Object Property Description HOME bubbles Returns whether or not a specific event is a bubbling event 2 cancelable Returns whether or not an event can have its default action prevented 2 currentTarget Returns the element whose event listeners triggered the event 2 defaultPrevented Returns whether or not the preventDefault() method was called for the event 3 eventPhase Returns which phase of the event flow is currently being evaluated 2 isTrusted Returns whether or not an event is trusted 3 target Returns the element that triggered the event 2 timeStamp Returns the time (in milliseconds relative to the epoch) at which the event was created 2 type Returns the name of the event 2 view Returns a reference to the Window object where the event occurred 2

Properties related to working with the mouse

Object Property Description HOME altKey Returns whether the “ALT” key was pressed when the mouse event was triggered 2 button Returns which mouse button was pressed when the mouse event was triggered 2 buttons Returns which mouse buttons were pressed when the mouse event was triggered 3 clientX Returns the horizontal coordinate of the mouse pointer, relative to the current window, when the
mouse event was triggered 2 clientY Returns the vertical coordinate of the mouse pointer, relative to the current window, when the
mouse event was triggered 2 ctrlKey Returns whether the “CTRL” key was pressed when the mouse event was triggered 2 detail Returns a number that indicates how many times the mouse was clicked 2 metaKey Returns whether the “META” key was pressed when an event was triggered 2 relatedTarget Returns the element related to the element that triggered the mouse event 2 screenX Returns the horizontal coordinate of the mouse pointer, relative to the screen, when an event was
triggered 2 screenY Returns the vertical coordinate of the mouse pointer, relative to the screen, when an event was
triggered 2 shiftKey Returns whether the “SHIFT” key was pressed when an event was triggered 2 which Returns which mouse button was pressed when the mouse event was triggered 2

Properties related to working with the keyboard

Object Property Description HOME altKey Returns whether the “ALT” key was pressed when the key event was triggered 2 ctrlKey Returns whether the “CTRL” key was pressed when the key event was triggered 2 charCode Returns the Unicode character code of the key that triggered the onkeypress event 2 key Returns the key value of the key represented by the event 3 keyCode Returns the Unicode character code of the key that triggered the onkeypress event, or the Unicode
key code of the key that triggered the onkeydown or onkeyup event 2 location Returns the location of a key on the keyboard or device 3 metaKey Returns whether the “meta” key was pressed when the key event was triggered 2 shiftKey Returns whether the “SHIFT” key was pressed when the key event was triggered 2 which Returns the Unicode character code of the key that triggered the onkeypress event, or the Unicode
key code of the key that triggered the onkeydown or onkeyup event 2

Property related to focus change

Evernt object property Property description HOME relatedTarget Returns the element related to the element that triggered the event 3

Animation related properties

Evernt object property Property description HOME animationName Returns the name of the animation elapsedTime Returns the number of seconds an animation has been running

Properties related to transition

Evernt object property Property description HOME propertyName Returns the name of the CSS property associated with the transition elapsedTime Returns the number of seconds a transition has been running

Properties related to scroll

Evernt object property Property description HOME deltaX Returns the horizontal scroll amount of a mouse wheel (x-axis) 3 deltaY Returns the vertical scroll amount of a mouse wheel (y-axis) 3 deltaZ Returns the scroll amount of a mouse wheel for the z-axis 3 deltaMode Returns a number that represents the unit of measurements for delta values (pixels, lines or pages) 3

Caching related property

Evernt object property Property description HOME persisted Returns whether the webpage was cached by the browser

A property related to the hash position on the page

Evernt propertyobject Property description HOME newURL Returns the URL of the document, after the hash has been changed oldURL Returns the URL of the document, before the hash was changed