How to change part of byte1[12] values ​​to byte2[4] values ​​in c#?

Question

C++ / C#

For example there is byte1[12] = '1','1','1','1','1','1','1','1','1','1','1' ,'1',
And byte2[4] = '2','3','4','5',
You need to replace the 5th to 8th bytes with byte2[4] to get '1',' 1','1','1','2','3','4','5','1','1','1','1',
Can this be done WITHOUT a loop?

Answer 1

byte2.CopyTo(byte1, 4);