I have some code and when I run it produces an error, saying: NoSuchMethod: the method 'XYZ' was called on null What does that mean and how do I fix it?

Have been seeing the term "Expando" used recently with Dart. Sounds interesting. The API did not provide much of a clue to me. An example or two could be most helpful! (Not sure if this is relat...

I'm new to Java and Android, and I'm working on my first test app. I've progressed with it, but I'm blocked with a Dialog. I show the dialog from the Activity like this: //BuyActivity.java publi...

I have a main class which should call a JavaFX application (SimpleSun) to get Information from the user. Currently I create an Object of the JavaFX class and start it, but that doesn't seem to work...

I would like to extend localStorage by executing some code each time a setting is fetched/stored. I could define a getter/setter for all existing properties of localStorage, but the problem lies in...