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 pending
• Cannot read property nodename
• Cannot read property defaultview
• Cannot read property words
• Cannot read property datatable
• Cannot read property foreach
• Cannot read property match
• Cannot read property reduce
• Cannot read property getelementsbytagname
• Cannot read property includes
• Cannot read property quesryselectorall
• Cannot read property keycode
• Cannot read property apply
• Cannot read property y
• Cannot read property hasownproperty
• Cannot read property width
• Cannot read property helpers
• Cannot read property prototype
• Cannot read property view
• Cannot read property add
• Cannot read property click
• Cannot read property xhr
• Cannot read property browserwindow
• Cannot read property concat
• Cannot read property html
• Cannot read property filter
• Cannot read property classname
• Cannot read property classlist
• Cannot read property checked
• Cannot read property editor
• Cannot read property validate
• Cannot read property rows
• Cannot read property uid
• Cannot read property slice
• Cannot read property keyup
• Cannot read property render
• Cannot read property ngmodule
• Cannot read property key
• Cannot read property findindex
• Cannot read property style
• Cannot read property type
• Cannot read property json
• Cannot read property fn
• Cannot read property use
• Cannot read property trim
• Cannot read property bridge
• Cannot read property queryselector
• Cannot read property height
• Cannot read property textcontent
• Cannot read property left
• Cannot read property play
• Cannot read property length
• Cannot read property then
• Cannot read property reset
• Cannot read property hide
• Cannot read property appendchild
• Cannot read property extend

Uncaught TypeError: Cannot read property '' of null