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 play
• Cannot read property bridge
• Cannot read property left
• Cannot read property document
• Cannot read property mouse
• Cannot read property zindex
• Cannot read property reset
• Cannot read property form
• Cannot read property header
• Cannot read property validate
• Cannot read property append
• Cannot read property match
• Cannot read property push
• Cannot read property ext
• Cannot read property indexof
• Cannot read property defaultview
• Cannot read property emit
• Cannot read property install
• Cannot read property width
• Cannot read property trim
• Cannot read property reload
• Cannot read property option
• Cannot read property innerhtml
• Cannot read property bind
• Cannot read property innertext
• Cannot read property createelement
• Cannot read property add
• Cannot read property rows
• Cannot read property constructor
• Cannot read property hasattribute
• Cannot read property split
• Cannot read property keyup
• Cannot read property reduce
• Cannot read property hasownproperty
• Cannot read property datatable
• Cannot read property length
• Cannot read property queuedepthsort
• Cannot read property findindex
• Cannot read property props
• Cannot read property value
• Cannot read property then
• Cannot read property uid
• Cannot read property textcontent
• Cannot read property jsonmodel
• Cannot read property websiteid
• Cannot read property ngmodule
• Cannot read property visible
• Cannot read property have
• Cannot read property 3
• Cannot read property error
• Cannot read property files
• Cannot read property preventdefault
• Cannot read property getelementsbyclassname
• Cannot read property zoneid
• Cannot read property json
• Cannot read property xe
• Cannot read property xhr

Uncaught TypeError: Cannot read property '' of null