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 dataset
• Cannot read property hasattribute
• Cannot read property click
• Cannot read property props
• Cannot read property constructor
• Cannot read property preventdefault
• Cannot read property zindex
• Cannot read property visible
• Cannot read property reset
• Cannot read property addmethod
• Cannot read property play
• Cannot read property includes
• Cannot read property keyboard
• Cannot read property browser
• Cannot read property focus
• Cannot read property style
• Cannot read property filter
• Cannot read property each
• Cannot read property use
• Cannot read property play
• Cannot read property contains
• Cannot read property foreach
• Cannot read property call
• Cannot read property websiteid
• Cannot read property query
• Cannot read property rows
• Cannot read property map
• Cannot read property mouse
• Cannot read property fn
• Cannot read property location
• Cannot read property y
• Cannot read property getattribute
• Cannot read property keycode
• Cannot read property zone
• Cannot read property innertext
• Cannot read property firstchild
• Cannot read property destroy
• Cannot read property prototype
• Cannot read property nodename
• Cannot read property height
• Cannot read property push
• Cannot read property xhr
• Cannot read property webkit
• Cannot read property editor
• Cannot read property hasownproperty
• Cannot read property 1
• Cannot read property key
• Cannot read property type
• Cannot read property removechild
• Cannot read property xe
• Cannot read property x
• Cannot read property add
• Cannot read property data
• Cannot read property target
• Cannot read property locals
• Cannot read property getitem
• Cannot read property set

Uncaught TypeError: Cannot read property '' of null