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 append
• Cannot read property keyboard
• Cannot read property zindex
• Cannot read property id
• Cannot read property history
• Cannot read property mouse
• Cannot read property map
• Cannot read property width
• Cannot read property remove
• Cannot read property removechild
• Cannot read property then
• Cannot read property getitem
• Cannot read property createelement
• Cannot read property height
• Cannot read property data
• Cannot read property locals
• Cannot read property touppercase
• Cannot read property ext
• Cannot read property quesryselectorall
• Cannot read property reset
• Cannot read property msie
• Cannot read property replace
• Cannot read property browserwindow
• Cannot read property apply
• Cannot read property init
• Cannot read property version
• Cannot read property hasownproperty
• Cannot read property textcontent
• Cannot read property xrm
• Cannot read property key
• Cannot read property display
• Cannot read property destroy
• Cannot read property which
• Cannot read property render
• Cannot read property parentnode
• Cannot read property addmethod
• Cannot read property getelementsbytagname
• Cannot read property classname
• Cannot read property split
• Cannot read property y
• Cannot read property state
• Cannot read property addeventlistener
• Cannot read property queryselector
• Cannot read property readtext
• Cannot read property getelementsbyclassname
• Cannot read property value
• Cannot read property includes
• Cannot read property each
• Cannot read property queuedepthsort
• Cannot read property visible
• Cannot read property rows
• Cannot read property style
• Cannot read property option
• Cannot read property error
• Cannot read property query
• Cannot read property top
• Cannot read property pending

Uncaught TypeError: Cannot read property '' of null