Uncaught TypeError: Cannot read property '' of undefined
JavaScript Error: Uncaught TypeError: Cannot read property '' of null
JavaScript TypeError is returned when an operand or argument passed to a function is incompatible with the type expected by that operator or function. This error occurs in the browser when you read a property or call a method on an undefined object.
There are a few variations of this error depending on the property you are trying to access. Sometimes instead of undefined it will output null:
Uncaught TypeError: Cannot read property '' of null
Cannot read property '' of undefined
Cannot read property '' of null
Undefined means that a variable has been declared, but the value of that variable has not yet been defined. In JavaScript, there are Undefined (type), undefined (value) and undefined (variable).
This error occurs when you try to call a method or try to access a property of a variable that does not exist (is not an object). This error occurs when we want to access a property on a variable whose value is undefined or null.
Null vs. Undefined in JavaScript The value "undefined" indicates that a variable has been declared, but no value has been assigned. On the other hand, "null" refers to a non-existent object, which basically means "empty" or "nothing". These are two values generally used to indicate the absence of something. Also, undefined and null are two distinct types: undefined is a type itself (undefined) while null is an object.
Other Javascript errors :
- Cannot read property appendchild
- Cannot read property write
- Cannot read property submit
- Cannot read property render
- Cannot read property emit
- Cannot read property option
- Cannot read property 10
- Cannot read property fn
- Cannot read property join
- Cannot read property addmethod
- Cannot read property zindex
- Cannot read property register
- Cannot read property location
- Cannot read property defaultview
- Cannot read property quesryselectorall
- Cannot read property append
- Cannot read property which
- Cannot read property msie
- Cannot read property form
- Cannot read property install
- Cannot read property remove
- Cannot read property keyup
- Cannot read property replace
- Cannot read property concat
- Cannot read property reload
- Cannot read property jspdf
- Cannot read property zoneid
- Cannot read property helpers
- Cannot read property uid
- Cannot read property trim
- Cannot read property queuedepthsort
- Cannot read property pending
- Cannot read property prototype
- Cannot read property xrm
- Cannot read property classlist
- Cannot read property tolowercase
- Cannot read property html
- Cannot read property getitem
- Cannot read property init
- Cannot read property toggle
- Cannot read property filter
- Cannot read property id
- Cannot read property bind
- Cannot read property view
- Cannot read property find
- Cannot read property set
- Cannot read property getelementsbyclassname
- Cannot read property setattribute
- Cannot read property editor
- Cannot read property adatasort
- Cannot read property hasownproperty
- Cannot read property hasattribute
- Cannot read property document
- Cannot read property classname
- Cannot read property includes
- Cannot read property firstchild
- Cannot read property nodename