jQuery plugin returning Cannot read property of undefined

Question

I m trying to do something i ve done numerous times  I can t figure out why this isn t working  No matter how i write the jQuery code  it doesn t work  menuitems i  action   just does NOT work  Below is Example 1 in which this example  no matter what item is clicked it returns the last item s action  in this example it s the alert  Forward      The 2nd returns undefined property  The full error below   My jQuery plugin is called like this  examples below are what happen with this same call       p   contextMenu                 name  Back           action function                alert  Back                        icon  http   cdn iconfinder net data icons crystalproject 16x16 actions agt back png                       name  Forward           action function                alert  Forward                        icon  http   cdn iconfinder net data icons crystalproject 16x16 actions agt forward png              Example 1   for  i in menuitems           lt li  gt              html    lt img src    menuitems i  icon    gt   menuitems i  name           class  o itemClass           click  function                menuitems i  action                     appendTo     o listClass       This returns an alert with Forward  no matter which item  Back or Forward  is clicked   Example 2   var len   menuitems length  for  var i   0  i  lt  len  i             lt li  gt              html    lt img src    menuitems i  icon    gt   menuitems i  name           click  function                menuitems i  action                        class  o itemClass        appendTo     o listClass       I get      Uncaught TypeError  Cannot read   property  action  of undefined   Other random things i tried were detaching the click and reattaching it outside of that appendTo   block  changed action   to newtest   to make sure it wasn t conflicting with any built in keywords  I also tried doing a    body   append   lt li gt  blah blah  lt  li gt    find  li   click function     blah blah      but it still returned the same thing  I m outta ideas

User · Answer

Usually that problem is that in the last iteration you have an empty object or undefine object. use console.log() inside you cicle to check that this doent happend.

Sometimes a prototype in some place add an extra element.

User · Answer

I had same problem with  parallax  plugin  I changed jQuery librery version to  jquery-1 6 4  from  jquery-1 10 2   And error cleared

User · Answer

The problem is that  i  is incremented  so by the time the click event is executed the value of i equals len  One possible solution is to capture the value of i inside a function   var len   menuitems length  for  var i   0  i  lt  len  i          function i              lt li  gt                html    lt img src    menuitems i  icon    gt   menuitems i  name             click  function                  menuitems i  action                            class  o itemClass          appendTo     o listClass          i       In the above sample  the anonymous function creates a new scope which captures the current value of i  so that when the click event is triggered the local variable is used instead of the i from the for loop

[javascript] jQuery plugin returning "Cannot read property of undefined"

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