almost_equals

Note

This is a point-in-time snapshot of the API documentation from January 2026. Going forward, we will not be maintaining a public copy of these references, and recommend users to refer to the built-in signature helpers available in the Hack LSP instead for complete and up-to-date information.

Compares two numbers to see if they are within epsilon of each other

namespace HH\Lib\Math;

function almost_equals(
  num $num_one,
  num $num_two,
  num $epsilon = 1.0E-8,
): bool;

If the difference equals epsilon this returns false.

default epsilon of .00000001.

When comparing large numbers consider passing in a large epsilon

Parameters

• num $num_one
• num $num_two
• num $epsilon = 1.0E-8

Returns

• bool