php获取指定范围内最接近数的方法

本文实例讲述了php获取指定范围内最接近数的方法。分享给大家供大家参考。具体实现方法如下：

    // 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)

希望本文所述对大家的php程序设计有所帮助。