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

Simply put, undefined means that a variable has been declared but has not yet been given a value. This particular error is probably the easiest to understand from an undefined point of view, because undefined is not considered an object type at all (but its own undefined type instead), and properties cannot belong to only to objects in JavaScript.
This error occurs when we want to access a property on a variable whose value is undefined or null. 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).

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 x
• Cannot read property extend
• Cannot read property left
• Cannot read property document
• Cannot read property document
• Cannot read property fn
• Cannot read property view
• Cannot read property key
• Cannot read property 3
• Cannot read property addmethod
• Cannot read property json
• Cannot read property jsonmodel
• Cannot read property replace
• Cannot read property join
• Cannot read property rows
• Cannot read property query
• Cannot read property findindex
• Cannot read property locals
• Cannot read property jspdf
• Cannot read property emit
• Cannot read property classlist
• Cannot read property target
• Cannot read property pending
• Cannot read property setattribute
• Cannot read property props
• Cannot read property msie
• Cannot read property then
• Cannot read property hasattribute
• Cannot read property option
• Cannot read property error
• Cannot read property getelementsbytagname
• Cannot read property find
• Cannot read property submit
• Cannot read property concat
• Cannot read property 2
• Cannot read property nodename
• Cannot read property touppercase
• Cannot read property location
• Cannot read property textcontent
• Cannot read property hide
• Cannot read property scrolltop
• Cannot read property browserwindow
• Cannot read property getattribute
• Cannot read property focus
• Cannot read property dataset
• Cannot read property queryselector
• Cannot read property validate
• Cannot read property defaultview
• Cannot read property play
• Cannot read property websiteid
• Cannot read property reset
• Cannot read property readtext
• Cannot read property play
• Cannot read property history
• Cannot read property visible
• Cannot read property datatable
• Cannot read property header

Uncaught TypeError: Cannot read property '' of null