Bit - Bitwise and Shift binary operator

About

Operator on bit.

See Reference/Operators/Bitwise_Operators

Bitwise binary operator may also be used as assignment operator

Type

  • the bitwise arithmetic operators (~, &, ^, and |)
  • and the shift operators (<<, >>, and >>>).

Arithmetic

The bitwise arithmetic operators

  • ~ (NOT)
  • & (AND)
  • ^ (XOR)
  • and | OR

They are also Boolean operator.

NOT (~)

  • ~, the Bitwise NOT Operator
// ~x is roughly the same as -(x+1)
console.log(~2);    // -(2+1) ==> -3

XOR (^) - Exclusive OR

The bitwise addition, modulo 2, of two bit strings of equal length.

The bitwise XOR expression follows the following rules:

0 ^ 0 = 0
0 ^ 1 = 1
1 ^ 0 = 1
1 ^ 1 = 0

Example

console.log(6 ^ 2); //  110 ^ 010 = 100 = 4

OR (|)

The bitwise OR expression follows the following rules:

0 | 0 = 0
0 | 1 = 1
1 | 0 = 1
1 | 1 = 1

Example:

console.log(6 | 2); //  110 ^ 010 = 110 = 6
console.log(8 | 1); //  1000 ^ 0001 = 1001 = 9

AND (&)

0 & 0 = 0
0 & 1 = 0
1 & 0 = 0
1 & 1 = 1

Shift

The shift operators shifts the digits to the left or to the right:

  • moving the bits to the left or to the right (if you need to position them inside a fix number of bit)
  • and/or multiplying or dividing by 2

List:

  • << - shift to the left (ie multiply by 2)
  • >> - shift to the right (divide by 2)
  • and >>>

Example / Demo:

  • The initial value of 1 in bit
const foo = '0001'; // 1
console.log(`Initial Value: bit: ${foo}, decimal ${parseInt(foo, 2)}`);
  • Shift one bit to the left (multiply by 2)
let fooShifted = parseInt(foo, 2) << 1
console.log(`shifted by one (x2): bit: ${fooShifted.toString(2)}, decimal: ${fooShifted}`);
  • Shift two bit to the left (2×2)
fooShifted = parseInt(foo, 2) << 2
console.log(`shifted by two (x2 x2): bit: ${fooShifted.toString(2)}, decimal: ${fooShifted}`);

Documentation / Reference


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