/**
 * 指定范围内返回上一个、下一个最接近的数字
 *
 * @param 
 * @author 编程之家 jb51.cc jb51.cc
 **/
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)