TypeError: can't define property 'x': 'obj' is not extensible.TypeError: can't assign to property 'x' on 'y': not an object.TypeError: can't access property 'x' of 'y'.

TypeError: X.prototype.y called on incompatible type.TypeError: Reduce of empty array with no initial value.TypeError: 'x' is not a non-null object.Synta圎rror: unterminated string literal.Synta圎rror: test for equality (=) mistyped as assignment (=)?.Synta圎rror: redeclaration of formal parameter 'x'.Variables defined inside a function cannot be accessed from anywhere outside the function, because the variable is defined only in the scope of the function function numbers() after property list var foo = 'bar' Ī variable needs to be available in the current context of execution.

It needs to be some string, so that the () method will work. The 'foo' variable isn't defined anywhere. Examples Variable not declared foo.substring(1) // ReferenceError: foo is not defined Put the tag that loads the library before your code that uses it. Note: When loading a library (such as jQuery), make sure it is loaded before you access library variables, such as '$'.

Javascript is defined