what is null.
null is the value of a reference variable when it doesn’t point to anything in memory. Think of it as a street sign with the name of a city on it, but no arrow, and the city doesn’t exist. 
You can compare against it in if-sentences to see if objects have been instantiated yet. Objects are null up until the point someone instantiates them using the “new” keyword:
object test; // null
test = new object(); // No longer null, points to an actual object
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Null denotes the absence of value; in other words, null is zero, as in the case of coffee with so little sugar that it is essentially null. Null is another word for invalid or lacking any legal authority.
The word null, which means “not any” in Latin, is used to describe the helpless, destitute null. If it was, it’s no longer there. Considering that null is essentially nothing, zero, zilch, nada, and nil. What is worse than this? Maybe being declared “null and void,” which is a legal phrase meaning that something is absolutely null. The word nullify, which implies to render anything void or cancel something out, is derived from the noun null.
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