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 :
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- Cannot read property browser
- Cannot read property document
- Cannot read property reduce
- Cannot read property dataset
- Cannot read property bind
- Cannot read property tolowercase
- Cannot read property hasownproperty
- Cannot read property keyboard
- Cannot read property appendchild
- Cannot read property ajax
- Cannot read property have
- Cannot read property mouse
- Cannot read property which
- Cannot read property left
- Cannot read property error
- Cannot read property register
- Cannot read property history
- Cannot read property then
- Cannot read property tostring
- Cannot read property call
- Cannot read property scrolltop
- Cannot read property click
- Cannot read property find
- Cannot read property document
- Cannot read property readtext
- Cannot read property sort
- Cannot read property push
- Cannot read property play
- Cannot read property webkit
- Cannot read property top
- Cannot read property uid
- Cannot read property getitem
- Cannot read property 2
- Cannot read property addmethod
- Cannot read property getters
- Cannot read property classname
- Cannot read property html
- Cannot read property keycode
- Cannot read property 3
- Cannot read property add
- Cannot read property bridge
- Cannot read property createelement
- Cannot read property play
- Cannot read property get
- Cannot read property removechild
- Cannot read property install
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- Cannot read property set
- Cannot read property reload
- Cannot read property hide
- Cannot read property xe
- Cannot read property 1
- Cannot read property state
- Cannot read property replace
- Cannot read property match
- Cannot read property visible