(StartA <= EndB) and (EndA >= StartB) Proof: Let ConditionA Mean that DateRange A Completely After DateRange B _ |—- DateRange A ——| |—Date Range B —–| _ (True if StartA > EndB) Let ConditionB Mean that DateRange A is Completely Before DateRange B |—- DateRange A —–| _ _ |—Date Range B —-| (True … Read more
An abstract function cannot have functionality. You’re basically saying, any child class MUST give their own version of this method, however it’s too general to even try to implement in the parent class. A virtual function, is basically saying look, here’s the functionality that may or may not be good enough for the child class. … Read more
Prefer composition over inheritance as it is more malleable / easy to modify later, but do not use a compose-always approach. With composition, it’s easy to change behavior on the fly with Dependency Injection / Setters. Inheritance is more rigid as most languages do not allow you to derive from more than one type. So … Read more
Consider a simple function that adds the first N natural numbers. (e.g. sum(5) = 0 + 1 + 2 + 3 + 4 + 5 = 15). Here is a simple JavaScript implementation that uses recursion: function recsum(x) { if (x === 0) { return 0; } else { return x + recsum(x – 1); … Read more
A function is a piece of code that is called by name. It can be passed data to operate on (i.e. the parameters) and can optionally return data (the return value). All data that is passed to a function is explicitly passed. A method is a piece of code that is called by a name … Read more
The best definition I’ve found so far is one by James Shore: “Dependency Injection” is a 25-dollar term for a 5-cent concept. […] Dependency injection means giving an object its instance variables. […]. There is an article by Martin Fowler that may prove useful, too. Dependency injection is basically providing the objects that an object … Read more
Binary floating point math is like this. In most programming languages, it is based on the IEEE 754 standard. The crux of the problem is that numbers are represented in this format as a whole number times a power of two; rational numbers (such as 0.1, which is 1/10) whose denominator is not a power … Read more