Rounding numbers down (v12)

Revision 12 of this benchmark created by Jack Rugile on

Description

Note that some of the listed alternatives to Math.floor() use bitwise operators, which convert numbers to a 32-bit sequence.

These alternatives will only work with positive signed 32-bit floats, i.e. numbers from 0 to +2,147,483,647 (2^31-1).

~~2147483647.1; // 2147483647
~~2147483648.1; // -2147483648

Preparation HTML

<script>
  var n = Math.PI; // 3.141592653589793
</script>

Test runner

Ready to run.

Testing in
TestOps/sec
Math.floor
Math.floor(n); // 3
ready
parseInt
parseInt(n, 10); // 3
ready
Double bitwise NOT
~~n; // 3
ready
Bitwise OR
n | n; // 3
ready
Bitwise OR with 0
n | 0; // 3
ready
Bitwise AND
n & n; // 3
ready
Bitwise left shift
n << 0; // 3
ready
round
Math.round(n); // 3
ready

Revisions

You can edit these tests or add more tests to this page by appending /edit to the URL.