Ruby - Bitwise OR and assignment operator
The Bitwise OR and assignment operator (|=) assigns the first operand a value equal to the result of Bitwise OR operation of two operands.
(x |= y) is equivalent to (x = x | y)
The Bitwise OR operator (|) is a binary operator which takes two bit patterns of equal length and performs the logical OR operation on each pair of corresponding bits. It returns 1 if either or both bits at the same position are 1, else returns 0.
Bit_1 | Bit_2 | Bit_1 | Bit_2 |
---|---|---|
0 | 0 | 0 |
1 | 0 | 1 |
0 | 1 | 1 |
1 | 1 | 1 |
The example below describes how bitwise OR operator works:
50 | 25 returns 59 50 -> 110010 (In Binary) | 25 -> | 011001 (In Binary) ---- -------- 59 <- 111011 (In Binary)
The code of using Bitwise OR operator (|) is given below:
x = 50 y = 25 #Bitwise OR and assignment operation x |= y #Displaying the result puts "x = #{x}"
The output of the above code will be:
x = 59
Example: Find largest power of 2 less than or equal to given number
Consider an integer 1000. In the bit-wise format, it can be written as 1111101000. However, all bits are not written here. A complete representation will be 32 bit representation as given below:
00000000000000000000001111101000
Performing
00000000000000000000001111111111
Adding one to this result and then right shifting the result by one place will give largest power of 2 less than or equal to 1000.
00000000000000000000001000000000
The below code will calculate the largest power of 2 less than or equal to given number.
def MaxPowerOfTwo(n) #changing all right side bits to 1. n |= (n>>1) n |= (n>>2) n |= (n>>4) n |= (n>>8) n |= (n>>16) #adding 1 to n makes smallest power #of 2 greater than given number n += 1 #right shift by one position makes #largest power of 2 less than or #equal to given number n >>= 1 return n end puts "MaxPowerOfTwo(100) = #{MaxPowerOfTwo(100)}" puts "MaxPowerOfTwo(500) = #{MaxPowerOfTwo(500)}" puts "MaxPowerOfTwo(1000) = #{MaxPowerOfTwo(1000)}"
The above code will give the following output:
MaxPowerOfTwo(100) = 64 MaxPowerOfTwo(500) = 256 MaxPowerOfTwo(1000) = 512
❮ Ruby - Operators