<How to replace only 4 bits of 1 byte?> I know I c...

# stackoverflow

[user]

How to replace only 4 bits of 1 byte?
I know I can store and retrieve 2 numbers of 4 bits inside 1 Byte like this :
// Store both numbers in one byte
byte firstNumber = 10;
byte secondNumber = 15;
byte bothNumbers = (byte) ((firstNumber > 4) & (byte) 0x0F);
secondNumber = (byte) (bothNumbers & 0x0F);

But how can I overwrite one of the two numbers (let's say the first one (10)) without touching the last 4 bits (15)?
// Store both numbers in one byte
byte firstNumber = 10;
byte secondNumber = 15;
byte bothNumbers = (byte)...