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 fn
• Cannot read property find
• Cannot read property queryselector
• Cannot read property nodetype
• Cannot read property formatdate
• Cannot read property editor
• Cannot read property helpers
• Cannot read property checked
• Cannot read property words
• Cannot read property zone
• Cannot read property websiteid
• Cannot read property jquery
• Cannot read property msie
• Cannot read property reduce
• Cannot read property map
• Cannot read property xhr
• Cannot read property preventdefault
• Cannot read property length
• Cannot read property key
• Cannot read property addmethod
• Cannot read property render
• Cannot read property foreach
• Cannot read property files
• Cannot read property xe
• Cannot read property query
• Cannot read property write
• Cannot read property dataset
• Cannot read property scrolltop
• Cannot read property createelement
• Cannot read property focus
• Cannot read property keyup
• Cannot read property version
• Cannot read property indexof
• Cannot read property readtext
• Cannot read property datatable
• Cannot read property width
• Cannot read property submit
• Cannot read property set
• Cannot read property firstchild
• Cannot read property emit
• Cannot read property classname
• Cannot read property data
• Cannot read property x
• Cannot read property join
• Cannot read property zoneid
• Cannot read property each
• Cannot read property bridge
• Cannot read property init
• Cannot read property extend
• Cannot read property html
• Cannot read property keycode
• Cannot read property getattribute
• Cannot read property display
• Cannot read property textcontent
• Cannot read property element
• Cannot read property split
• Cannot read property header

Uncaught TypeError: Cannot read property '' of null