keycode and charcode

Question

Why do people write statement like  e keyCode   e keyCode   e charCode   Some people also use e which  Could someone please explain

User · Answer

It is a conditional statement   If browser supprts e keyCode then take e keyCode else e charCode   It is similar to  var code   event keyCode    event charCode   event keyCode  Returns the Unicode value of a non-character key in a keypress event or any key in any other type of keyboard event   event charCode  Returns the Unicode value of a character key pressed during a keypress event

User · Answer

keyCode and which represent the actual keyboard key pressed in the form of a numeric value   The reason both exist is that keyCode is available within Internet Explorer while which is available in W3C browsers like FireFox   charCode is similar  but in this case you retrieve the Unicode value of the character pressed   For example  the letter  A    The JavaScript expression   var keyCode   e keyCode   e keyCode   e charCode    Essentially says the following   If the e keyCode property exists  set variable keyCode to its value   Otherwise  set variable keyCode to the value of the e charCode property   Note that retrieving the keyCode or charCode properties typically involve figuring out differences between the event models in IE and in W3C   Some entails writing code like the following       get the event object  either window event for IE   or the parameter e for other browsers    var evt   window event   window event   e      get the numeric value of the key pressed  either   event keyCode for IE for e which for other browsers    var keyCode   evt keyCode   evt keyCode   e which    EDIT  Corrections to my explanation of charCode as per Tor Haugen s comments

User · Answer

The property event which is added when using jQuery to avoid browser differences  See docs   The which property will be undefined if you are not using jQuery

User · Answer

Handling key events consistently is not at all easy   Firstly  there are two different types of codes  keyboard codes  a number representing the key on the keyboard the user pressed  and character codes  a number representing a Unicode character   You can only reliably get character codes in the keypress event  Do not try to get character codes for keyup and keydown events   Secondly  you get different sets of values in a keypress event to what you get in a keyup or keydown event   I recommend this page as a useful resource  As a summary   If you re interested in detecting a user typing a character  use the keypress event  IE bizarrely only stores the character code in keyCode while all other browsers store it in which  Some  but not all  browsers also store it in charCode and or keyCode  An example keypress handler   function evt      evt   evt    window event    var charCode   evt which    evt keyCode    var charStr   String fromCharCode charCode     alert charStr       If you re interested in detecting a non-printable key  such as a cursor key   use the keydown event  Here keyCode is always the property to use  Note that keyup events have the same properties   function evt      evt   evt    window event    var keyCode   evt keyCode        Check for left arrow key   if  keyCode    37        alert  Left arrow

User · Answer

Okay  here are the explanations   e keyCode - used to get the number that represents the key on the keyboard  e charCode - a number that represents the unicode character of the key on keyboard   e which -  jQuery specific  is a property introduced in jQuery  DO Not use in plain javascript   Below is the code snippet to get the keyCode and charCode   lt script gt     get key code function getKey event      event   event    window event    var keyCode   event which    event keyCode    alert keyCode         get char code function getChar event      event   event    window event    var keyCode   event which    event keyCode    var typedChar   String fromCharCode keyCode     alert typedChar      lt  script gt    Live example of Getting keyCode and charCode in JavaScript

User · Answer

I  being people myself  wrote this statement because I wanted to detect the key which the user typed on the keyboard across different browsers   In firefox for example  characters have   0 charCode and 0 keyCode  and keys such as arrows  amp  backspace have   0 keyCode and 0 charCode   However  using this statement can be problematic as  collisions  are possible  For example  if you want to distinguish between the Delete and the Period keys  this won t work  as the Delete has keyCode   46 and the Period has charCode   46

[javascript] keycode and charcode

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