bits

Bit Manipulation

Get Bit

This method shifts the relevant bit to the zeroth position. Then we perform AND operation with one which has bit pattern like 0001. This clears all bits from the original number except the relevant one. If the relevant bit is one, the result is 1, otherwise the result is 0.

See getBit function for further details.

Set Bit

This method shifts 1 over by bitPosition bits, creating a value that looks like 00100. Then we perform OR operation that sets specific bit into 1 but it does not affect on other bits of the number.

See setBit function for further details.

Clear Bit

This method shifts 1 over by bitPosition bits, creating a value that looks like 00100. Than it inverts this mask to get the number that looks like 11011. Then AND operation is being applied to both the number and the mask. That operation unsets the bit.

See clearBit function for further details.

Update Bit

This method is a combination of "Clear Bit" and "Set Bit" methods.

See updateBit function for further details.

Multiply By Two

This method shifts original number by one bit to the left. Thus all binary number components (powers of two) are being multiplying by two and thus the number itself is being multiplied by two.

Before the shift
Number: 0b0101 = 5
Powers of two: 0 + 2^2 + 0 + 2^0 

After the shift
Number: 0b1010 = 10
Powers of two: 2^3 + 0 + 2^1 + 0 

See multiplyByTwo function for further details.

Divide By Two

This method shifts original number by one bit to the right. Thus all binary number components (powers of two) are being divided by two and thus the number itself is being divided by two without remainder.

Before the shift
Number: 0b0101 = 5
Powers of two: 0 + 2^2 + 0 + 2^0 

After the shift
Number: 0b0010 = 2
Powers of two: 0 + 0 + 2^1 + 0 

See divideByTwo function for further details.

Switch Sign

This method make positive numbers to be negative and backwards. To do so it uses "Twos Complement" approach which does it by inverting all of the bits of the number and adding 1 to it.

1101 -3
1110 -2
1111 -1
0000  0
0001  1
0010  2
0011  3

See switchSign function for further details.

References

• Bit Manipulation on YouTube
• Negative Numbers in binary on YouTube
• Bit Hacks on stanford.edu