Uncaught TypeError: Cannot read property '' of undefined
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 :
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- Cannot read property view
- Cannot read property xhr
- Cannot read property find
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- Cannot read property match
- Cannot read property queuedepthsort
- Cannot read property constructor
- Cannot read property target
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- Cannot read property remove
- Cannot read property parentnode
- Cannot read property setstate
- Cannot read property form
- Cannot read property queryselector
- Cannot read property query
- Cannot read property have
- Cannot read property version
- Cannot read property history
- Cannot read property xlsx
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- Cannot read property get
- Cannot read property quesryselectorall
- Cannot read property jsonmodel
- Cannot read property indexof
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- Cannot read property value
- Cannot read property error
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- Cannot read property document
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- Cannot read property keyup
- Cannot read property write
- Cannot read property which