php获取指定范围内最接近数的方法

// returns the next higher or lower number
function nextrelatednumber($number, $range){  
  $r = $number % $range;
  $f = $number - $r;
  $b = round($r / $range, 0);
  return ($b == 1) ? $f + $range : $f;  
}
// returns the next higher number
function nexthighernumber($number, $range){  
  $r = $number % $range;
  $f = $number - $r;
  $b = ceil($r / $range);
  return ($b == 1) ? $f + $range : $f;  
}
// returns the next lower number
function nextlowernumber($number, $range){  
  $r = $number % $range;
  $f = $number - $r;
  $b = floor($r / $range);
  return ($b == 1) ? $f + $range : $f;  
}
// returns the next related number from an array
function nextnumberarray($number, $numberrangearray){
  $w = 0;
  $c = -1;
  $abstand = 0;
  $l = count($numberrangearray);    
  for($pos=0; $pos < $l; $pos++){
    $n = $numberrangearray[$pos];
    $abstand = ($n < $number) ? $number - $n : $n - $number;
    if ($c == -1){
      $c = $abstand;
      continue;
    }
    else if ($abstand < $c){
      $c = $abstand;
      $w = $pos;
    }
  }
  return $numberrangearray[$w];
}
 
// examples
// --------
// 0 10 20 30 40 50 ...
print 'nextrelatednumber: ';
print nextrelatednumber(44, 10) . "n";
// returns --> 40
// 0 20 40 60 80 100 ...
print 'nexthighernumber: ';
print nexthighernumber(41, 20) . "n";
// returns --> 60
// 0 5 10 15 20 25 30 35 ...
print 'nextlowernumber: ';
print nextlowernumber(57, 5) . "n";
// returns --> 55
// example with array
print 'nextnumberarray: ';
print nextnumberarray(45, array(3, 8, 19, 34, 56, 89)) . "n";
// returns --> 34
// (45 is between 34 and 56 but 34 is the next)