How to Set a Specific Bit in a Byte Variable in Java

How can I set a specific bit in a byte variable in Java?

if ((my_byte & (1 << i)) == 0) {
    // Bit i is not set, do something
}

Setting specific bits in a byte variable in Java can be easily accomplished using bitwise operations. These operations allow you to manipulate bits efficiently and directly.

// Setting a specific bit to 1
byte myByte = 0b00000000;  // initial byte value
int i = 3;  // The bit position to set (0-based index)
myByte |= (1 << i);  // This sets the 4th bit to 1 (0b00001000)

// Setting a specific bit to 0
myByte &= ~(1 << i);  // This sets the 4th bit back to 0 (0b00000000)

Causes

• Misunderstanding of bitwise operators and their usage in Java.
• Lack of knowledge about how to combine bitwise AND, OR, and NOT operations.

Solutions

• Use the bitwise OR operator to set a bit to 1.
• Use the bitwise AND operator with NOT to set a bit to 0.

Mistake: Using the wrong operator to set a bit. For example, using '&' instead of '|'.

Solution: Use the bitwise OR operator '|' to set a bit to 1.

Mistake: Trying to directly assign to a bit position instead of using bitwise manipulation.

Solution: Always perform bitwise operations to change individual bits in a byte.