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
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.
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- Cannot read property 10
- Cannot read property form
- Cannot read property classname
- Cannot read property split
- Cannot read property header
- Cannot read property html
- Cannot read property zindex
- Cannot read property files
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- Cannot read property getters
- Cannot read property reset
- Cannot read property set
- Cannot read property jquery
- Cannot read property top
- Cannot read property getitem
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- Cannot read property readtext
- Cannot read property rows
- Cannot read property each
- Cannot read property emit
- Cannot read property left
- Cannot read property textcontent
- Cannot read property preventdefault
- Cannot read property add
- Cannot read property 1
- Cannot read property get
- Cannot read property trim
- Cannot read property append
- Cannot read property browserwindow
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- Cannot read property hide
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- Cannot read property scrolltop
- Cannot read property view
- Cannot read property hasownproperty
- Cannot read property submit
- Cannot read property use
- Cannot read property tostring
- Cannot read property state
- Cannot read property document
- Cannot read property formatdate
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- Cannot read property innerhtml
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- Cannot read property webkit
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- Cannot read property fn
- Cannot read property register
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- Cannot read property keyboard