Plot Points in HoloViews
Hands on the time Module in Python
The code below returns the execution time in seconds.
Collections in Kotlin
Fold vs Reduce¶
fold takes an initial value,
and the first invocation of the lambda you pass to it
will receive that initial value
and the first element of the collection as parameters.
reduce doesn't take an initial value,
but instead starts with the first element of the collection as the accumulator (called sum in the following example).
Object Oriented Programming in Java
Tips and Traps¶
A static method cannot be abstract in Java. For refer to this discussion on Stackoverflow for rationale behind it. If you need the two together, what you are looking is probably singleton object with inheritance.
Singleton objects are more flexible and useful than static methods in Java. Please refer to Singleton Pattern Versus Static Class
Implement Singleton in Java
An implementation of the singleton pattern must:
- ensure that only one instance of the singleton class ever exists;
- and provide global access to that instance.
Typically, this is done by:
- declaring all constructors of the class to be private;
- and providing a static method that returns a reference to the instance.
The instance is usually stored as a private static variable; the instance is created when the variable is initialized, at some point before the static method is first called. The following is a sample implementation written in Java.