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 click
• Cannot read property ajax
• Cannot read property innerhtml
• Cannot read property getters
• Cannot read property remove
• Cannot read property addmethod
• Cannot read property browser
• Cannot read property then
• Cannot read property register
• Cannot read property which
• Cannot read property contains
• Cannot read property slice
• Cannot read property helpers
• Cannot read property reset
• Cannot read property reload
• Cannot read property jspdf
• Cannot read property find
• Cannot read property constructor
• Cannot read property zindex
• Cannot read property add
• Cannot read property focus
• Cannot read property queryselector
• Cannot read property emit
• Cannot read property play
• Cannot read property rows
• Cannot read property extend
• Cannot read property use
• Cannot read property keyboard
• Cannot read property prototype
• Cannot read property join
• Cannot read property apply
• Cannot read property removechild
• Cannot read property xhr
• Cannot read property formatdate
• Cannot read property style
• Cannot read property query
• Cannot read property width
• Cannot read property setattribute
• Cannot read property readtext
• Cannot read property play
• Cannot read property destroy
• Cannot read property createdocumentfragment
• Cannot read property document
• Cannot read property textcontent
• Cannot read property state
• Cannot read property concat
• Cannot read property document
• Cannot read property hide
• Cannot read property key
• Cannot read property history
• Cannot read property json
• Cannot read property y
• Cannot read property element
• Cannot read property includes
• Cannot read property map
• Cannot read property height
• Cannot read property foreach

Uncaught TypeError: Cannot read property '' of null