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 split
- Cannot read property set
- Cannot read property join
- Cannot read property left
- Cannot read property state
- Cannot read property 3
- Cannot read property split
- Cannot read property keyboard
- Cannot read property hasownproperty
- Cannot read property get
- Cannot read property document
- Cannot read property add
- Cannot read property dataset
- Cannot read property addeventlistener
- Cannot read property helpers
- Cannot read property init
- Cannot read property reduce
- Cannot read property play
- Cannot read property indexof
- Cannot read property webkit
- Cannot read property have
- Cannot read property props
- Cannot read property header
- Cannot read property visible
- Cannot read property bind
- Cannot read property nodename
- Cannot read property msie
- Cannot read property adatasort
- Cannot read property 1
- Cannot read property use
- Cannot read property filter
- Cannot read property getitem
- Cannot read property slice
- Cannot read property firstchild
- Cannot read property remove
- Cannot read property browser
- Cannot read property zindex
- Cannot read property type
- Cannot read property 10
- Cannot read property pending
- Cannot read property error
- Cannot read property length
- Cannot read property apply
- Cannot read property mouse
- Cannot read property reset
- Cannot read property ajax
- Cannot read property tostring
- Cannot read property xhr
- Cannot read property constructor
- Cannot read property removechild
- Cannot read property zone
- Cannot read property emit
- Cannot read property getelementsbytagname
- Cannot read property location
- Cannot read property datatable
- Cannot read property addmethod
- Cannot read property call