TypeError: thrown when a value is of the wrong type — ECMAScript v3: Object → Error → TypeError


new TypeError( )
new TypeError(message)



An optional error message that provides details about the exception. If specified, this argument is used as the value for the message property of the TypeError object.


A newly constructed TypeError object. If the message argument is specified, the Error object uses it as the value of its message property; otherwise, it uses an implementation-defined default string as the value of that property. When the TypeError( ) constructor is called as a function, without the new operator, it behaves just as it does when called with the new operator.



An error message that provides details about the exception. This property holds the string passed to the constructor, or an implementation-defined default string. See Error.message for details.


A string that specifies the type of the exception. All TypeError objects inherit the value “TypeError” for this property.


An instance of the TypeError class is thrown when a value is not of the type expected. This happens most often when you attempt to access a property of a null or undefined value. It can also occur if you invoke a method defined by one class on an object that is an instance of some other class, or if you use the new operator with a value that is not a constructor function, for example. JavaScript implementations are also permitted to ...

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