So, here's how a HashMap works behind the scenes. When you create a HashMap, what the Java virtual machine does is it creates a single-dimensional array to hold all of your data, to hold everything ...

An array in Java is a type of variable that can store multiple values. It stores these values based on a key that can be used to subsequently look up that information. Arrays can be useful for ...

If this is an application requirement, the three best ways to solve the ‘multiple values per key in a map in Java’ problem are: Stick with the standard APIs and add a collection class like a ‘Vector’ ...