Checks if two numbers are approximately equal to each other.

Use abs() to compare the absolute difference of the two values to $epsilon.
Omit the third parameter, $epsilon, to use a default value of 0.001.

代码实现

function approximatelyEqual($number1, $number2, $epsilon = 0.001)
{
  return abs($number1 - $number2) < $epsilon;
}

使用样例

approximatelyEqual(10.0, 10.00001); // true

approximatelyEqual(10.0, 10.01); // false