PHP convert decimal into fraction and back?

Question

I want the user to be able to type in a fraction like:

 1/2
 2 1/4
 3

And convert it into its corresponding decimal, to be saved in MySQL,

Answer 1

I made a blog post with a couple solutions for this, the most recent approach I took is: http://www.carlosabundis.com/2014/03/25/converting-decimals-to-fractions-with-php-v2/

    function dec2fracso($dec){
    //Negative number flag.
    $num=$dec;
    if($num<0){
        $neg=true;
    }else{
        $neg=false;
    }

    //Extracts 2 strings from input number
    $decarr=explode('.',(string)$dec);

    //Checks for divided by zero input.
    if($decarr[1]==0){
        $decarr[1]=1;
        $fraccion[0]=$decarr[0];
        $fraccion[1]=$decarr[1];
        return $fraccion;
    }

    //Calculates the divisor before simplification.
    $long=strlen($decarr[1]);
    $div="1";
    for($x=0;$x<$long;$x++){
        $div.="0";
    }

    //Gets the greatest common divisor.
    $x=(int)$decarr[1];
    $y=(int)$div;
    $gcd=gmp_strval(gmp_gcd($x,$y));

    //Calculates the result and fills the array with the correct sign.
    if($neg){
        $fraccion[0]=((abs($decarr[0])*($y/$gcd))+($x/$gcd))*(-1);
    }else{
        $fraccion[0]=(abs($decarr[0])*($y/$gcd))+($x/$gcd);
    }
    $fraccion[1]=($y/$gcd);
    return $fraccion;
}