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 queuedepthsort
• Cannot read property setattribute
• Cannot read property classname
• Cannot read property header
• Cannot read property push
• Cannot read property focus
• Cannot read property sort
• Cannot read property x
• Cannot read property add
• Cannot read property split
• Cannot read property getitem
• Cannot read property checked
• Cannot read property async
• Cannot read property top
• Cannot read property ngmodule
• Cannot read property bind
• Cannot read property xhr
• Cannot read property getelementsbyclassname
• Cannot read property element
• Cannot read property nodename
• Cannot read property 1
• Cannot read property touppercase
• Cannot read property textcontent
• Cannot read property use
• Cannot read property addeventlistener
• Cannot read property keyup
• Cannot read property reset
• Cannot read property validate
• Cannot read property rows
• Cannot read property keyboard
• Cannot read property bind
• Cannot read property getters
• Cannot read property add
• Cannot read property style
• Cannot read property addmethod
• Cannot read property width
• Cannot read property prototype
• Cannot read property locals
• Cannot read property toggle
• Cannot read property 3
• Cannot read property extend
• Cannot read property getelementsbytagname
• Cannot read property set
• Cannot read property websiteid
• Cannot read property slice
• Cannot read property tostring
• Cannot read property foreach
• Cannot read property pending
• Cannot read property hasownproperty
• Cannot read property name
• Cannot read property firstchild
• Cannot read property html
• Cannot read property constructor
• Cannot read property words
• Cannot read property createdocumentfragment
• Cannot read property version
• Cannot read property trim

Uncaught TypeError: Cannot read property '' of null