Compares two objects and returns a value indicating whether one is less than, equal to, or greater than the other.
A signed integer that indicates the relative values of x and y, as shown in the following table.
Less than zero
x is less than y.
x equals y.
Greater than zero
x is greater than y.
The preferred implementation is to use the IComparable.CompareTo(object) method of one of the parameters.
Comparing null with any type is allowed and does not generate an exception when using IComparable. When sorting, null is considered to be less than any other object.