Clamps $num within the inclusive range specified by the boundary values $a and $b.

If $num falls within the range, return $num.
Otherwise, return the nearest number in the range, using min() and max().

代码实现

function clampNumber($num, $a, $b)
{
  return max(min($num, max($a, $b)), min($a, $b));
}

使用样例

clampNumber(2, 3, 5); // 3
clampNumber(1, -1, -5); // -1