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Igor Yamshchykov
24,397 PointsNull and undefined difference?
What is actual difference between null and undefined ? When do both of them appear, and what are the special cases when they appear? What is appropriate use ? should I assign null to a variable that I want to be null or undefined ? And Why ? Would actually appreciate some article about it. Thank you
Igor Yamshchykov
24,397 PointsThank you a lot !
1 Answer
Jonathan Grieve
Treehouse Moderator 91,253 PointsYea Mithun was right.
Null is an empty value, like an array index referencing a key that doesn't exist or has nothing in it.
Undefined is a variable that has been referenced but doesn't actually exist.
Mithun B
Courses Plus Student 748 PointsMithun B
Courses Plus Student 748 Pointsnull is empty. It has no value and it is also not a string, variable, array or an object.
Undefined is a something that we forgot to define. Like if you forgot to assign 'function' to 'function crossCut(){}', crossCut will be undefined. JavaScript is not able to figure out if you created function or not.
I don't know if this is right. I tried my best with what I know.
Hope this helps.