PHP Round decimals always up to the nearest highest decimal

Question

I would like to create a rounding methode to round decimals always up to the closest highest decimal value.

for example: 51.13 => 51.20 or 22.33 => 23.40 but lets say 30.10 stays 30.10

Is this even possible? Sorry if my explonation is bad but my math english is not the best.

Answer 1

maybe custom function for rounding ?

something like this

    $inputNumber=51.13;
    
        function round2deci($number){
        $explode = explode(".", $number);
        /// 51.13 == 51.ab
        $a = substr($explode[1], 0, 1);
        $b =  substr($explode[1], 1, 2);
        // fix for 51.91
        if($a == 9){
        $explode[0]++;
        $a = 0;
        $b = 0;
        
    }
        if($b > 0){
            $a++;
        }
        echo $explode[0].".".$a."0";
        }
        
        round2deci($inputNumber);

and result is :

51.20

Answer 2

I found this answer on the php.net website under the ceil docs that does exactly what you want.

I've added an improved version below which returns a pure float where you'd be able to apply number_format to preserve the trailing zeros of the decimals:

function ceil_dec(float $number, int $precision = 2, string $separator = '.') : float
{
    $numberpart    = explode($separator, (string)$number);
    $numberpart[1] = substr_replace($numberpart[1], $separator, $precision, 0);
    if ($numberpart[0] >= 0) {
        $numberpart[1] = ceil($numberpart[1]);
    } else {
        $numberpart[1] = floor($numberpart[1]);
    }

    $ceil_number = [$numberpart[0], $numberpart[1]];

    return (float)implode($separator, $ceil_number);
}

var_dump(
    ceil_dec(10.23,1)
);

The above code is good for PHP 7.0 and above, and with declare(strict_types = 1) enabled.