Bit Manipulation

• 找到最低位的1

  n & -n
  /*
  6 ^ -6 = 110 ^ 010 = 010
  */

• 消掉最低位的1

  n & (n-1)

• 檢查是不是$2^n$

  const isPowerOfTwo = (x !== 0) && ((n & (n - 1) === 0))

XOR

• Swap two varibles

  a = 4
  b = 6
  a = a ^ b
  b = a ^ b
  a = a ^ b
  console.log(a, b) // 6 4

Reference

• Bit manipulation
• Bitwise operation
• Bit Twiddling Hacks