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 bridge
• Cannot read property touppercase
• Cannot read property words
• Cannot read property websiteid
• Cannot read property apply
• Cannot read property pending
• Cannot read property add
• Cannot read property left
• Cannot read property then
• Cannot read property getelementsbyclassname
• Cannot read property quesryselectorall
• Cannot read property files
• Cannot read property document
• Cannot read property destroy
• Cannot read property webkit
• Cannot read property id
• Cannot read property jquery
• Cannot read property firstchild
• Cannot read property focus
• Cannot read property tolowercase
• Cannot read property visible
• Cannot read property document
• Cannot read property y
• Cannot read property zone
• Cannot read property reload
• Cannot read property set
• Cannot read property option
• Cannot read property indexof
• Cannot read property datatable
• Cannot read property split
• Cannot read property setstate
• Cannot read property name
• Cannot read property which
• Cannot read property map
• Cannot read property xe
• Cannot read property nodename
• Cannot read property state
• Cannot read property jspdf
• Cannot read property keyup
• Cannot read property jsonmodel
• Cannot read property trim
• Cannot read property reset
• Cannot read property editor
• Cannot read property hasownproperty
• Cannot read property keycode
• Cannot read property extend
• Cannot read property query
• Cannot read property style
• Cannot read property checked
• Cannot read property version
• Cannot read property getitem
• Cannot read property json
• Cannot read property ext
• Cannot read property queryselector
• Cannot read property msie
• Cannot read property removechild
• Cannot read property init

Uncaught TypeError: Cannot read property '' of null