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 emit
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• Cannot read property editor
• Cannot read property y
• Cannot read property files
• Cannot read property keyboard
• Cannot read property textcontent
• Cannot read property nodetype
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• Cannot read property use
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• Cannot read property filter
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• Cannot read property 3
• Cannot read property helpers
• Cannot read property form
• Cannot read property appendchild
• Cannot read property innertext
• Cannot read property visible
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• Cannot read property add
• Cannot read property find
• Cannot read property uid
• Cannot read property zindex
• Cannot read property map
• Cannot read property quesryselectorall
• Cannot read property document
• Cannot read property browser
• Cannot read property rows
• Cannot read property which
• Cannot read property locals
• Cannot read property each
• Cannot read property jspdf
• Cannot read property msie
• Cannot read property prototype
• Cannot read property join
• Cannot read property removechild
• Cannot read property value
• Cannot read property element
• Cannot read property length
• Cannot read property ajax
• Cannot read property call
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• Cannot read property push
• Cannot read property set
• Cannot read property tostring
• Cannot read property nodename
• Cannot read property setattribute
• Cannot read property width
• Cannot read property split
• Cannot read property focus
• Cannot read property keyup
• Cannot read property add

Uncaught TypeError: Cannot read property '' of null