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COMMON ERROR IN JS

COMMON ERROR IN JS

TypeError: Cannot read property ‘length’

     This kind of error occurs when we are reading length property for       an undefined variable.

FIX    

To fix this we need to check whether the data type assigned to that variable have the length property

Uncaught TypeError: Cannot set property

 This kind of error occur when we are  trying to set a property for some data type which doesn’t have Property .For Example data type undefined doesn’t have any property

FIX    

To fix this we need to check whether the data type assigned to that variable have any property or not

Uncaught TypeError: Cannot read property

This kind of error occur when we are trying to access the defined variables/function/data

FIX    

To fix this we need to check whether the data has some value and it not equal to undefined

TypeError: ‘undefined’ is not an object (evaluating

    This is an error that occurs in Safari when you read a property or call a method on an undefined object. You can test this very easily in the Safari Developer Console. This is essentially the same as the above error for Chrome, but Safari uses a different error message.

FIX    

To fix this we need to check whether the data has some value and it not equal to undefined

 

TypeError: null is not an object (evaluating

        This is an error that occurs in Safari when you read a property or call a method on a null object.

FIX

        To fix this error we need to add an event listener that will notify           us when the page is ready. Once the addEventListener is fired, the init() method can make use of the DOM elements

 (unknown): Script error

        The Script error occurs when an uncaught JavaScript error crosses domain boundaries in violation of the cross-origin policy.

FIX    

        Setting the Access-Control-Allow-Origin header to * signifies that the resource can be accessed properly from any domain

TypeError: Object doesn’t support property

        This is an error that occurs in IE when you call an undefined method.

FIX    

        To fix this error check whether this.function is not undefined

TypeError: ‘undefined’ is not a function

This is an error that occurs in Chrome when you call an undefined function.

Uncaught RangeError

        This is an error that occurs in Chrome when you call a recursive function that does not terminate. It may also happen if you pass a value to a function that is out of range.

FIX   

        To fix this error  add  number in the range of function

ReferenceError: event is not defined

        This error is thrown when you try to access a variable that is undefined or is outside the   current scope.

FIX

        To fix this error when using the event handling system, make sure we use the event object passed in as a parameter.


Reference

https://rollbar.com/blog/top-10-javascript-errors/

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