PHP dropping decimals without rounding up

Question

I want to drop off decimals without rounding up. For example if I have 1.505, I want to drop last decimal and value should be 1.50. Is there such a function in PHP?

Answer 1

Maybe it's too late, but here's a good approach:

    $getTruncatedValue = function( $value, $precision )
    {
        //Casts provided value
        $value = ( string )$value;

        //Gets pattern matches
        preg_match( "/(-+)?\d+(\.\d{1,".$precision."})?/" , $value, $matches );

        //Returns the full pattern match
        return $matches[0];            
    };

    var_dump
    (
        $getTruncatedValue(1.123,1),   //string(3) "1.1"
        $getTruncatedValue(1.345,2),   //string(4) "1.34"
        $getTruncatedValue(1.678,3),   //string(5) "1.678"
        $getTruncatedValue(1.90123,4)  //string(6) "1.9012"  
    );

• The only pitfall in this approach may be the need to use a Regular Expression (which sometimes could bring a performance penalty).

Note: It's quite hard to find a native approach to truncate decimals, and I think it's not possible to perform that using sprintf and other string-related functions.