Collections.sort implementation

Question

I can not understand the method implementation and the logic of Collections.sort method. Here is the method implementation i found,

public static 

        

Answer 1

First of all this method return type is void

Because it's in-place implementation. List that passed to method will be sorted

What is > does in the method signature?

To compare results that extends Comparable interface for type T and it's children.

Object[] a = list.toArray();

Convert list to plain array.

What is the purpose of using Array.sort here?

Sorting of array.

i.set((T)a[j]);

assign to list elements in sorted order from array