Q:What does the term immutable mean?
A:The data value may not be changed. Note: The variable value may be changed, but the original immutable data value was discarded and a new data value was created in memory.
Q:System.String 和System.Text.StringBuilder 的区别？
Q:System.Array.CopyTo( ) 和 System.Array.Clone( )区别?
A:The Clone( ) method returns a new array ( a shallow copy ) object containing all the elements in the original array. The CopyTo( ) method copies the elements into another existing array. Both perform a shallow copy. A shallow copy means the contents ( each array element ) contains references to the same object as the elements in the original array. A deep copy ( which neither of these methods performs ) would create a new instance of each element's object, resulting in a different, yet identacle object.