Differences between a non-generic set and a generic set

Differences between a non-generic set and a generic set
ArrayList array = new ArrayList (); array. add ("123"); array. add ("test"); array. add (300); Console. writeLine (array [2]); View Code

Adding such a non-generic set object will go through a packing process without knowing the type of the added object.

When Console. WriteLine (array [2]) is output, the box is split.

Therefore, in terms of performance, we can avoid such a situation.

List <int> list = new List <int> (); list. Add (1); list. Add (2); View Code

The type of such a generic set object is defined as int. in JIT, you no longer need to binning or unboxing.

 

Another difference between generics and non-generics is that for type constraints, generics are defined based on type security.