Why do some people use the List base class to instantiate a new ArrayList?

Question

I keep coming across code where people instantiate a new ArrayList and assign it to the List interface, like this:

List names = new ArrayList&l         


        

Answer 1

Such code doesn't use the List class, it declares the variable as being of type List. This is called abstraction

List is an interface, which defines what methods the actual class has, without specifying which actual class is used.

Although not a big deal here, this practice can be very important, even essential in more complexes situations. It's good practice to always follow this pattern.