PHP codes to find num and denom of fractions

[msu_math]

Unlike integers and floats, addition and subtraction of several fractions (rational number) require finding least common multiple (LCM) of the denominators of those fractions. Also, simplifying a fractions requires finding greatest common divisor (GCD) of both numerator and denominator of that fractions.

Here, we quote the PHP codes to determine the numerator and denominator of a fraction. Note that both of the following functions recall the function FracCheck() which is included in the previously posted related articles.


function FracNumer($A)

{
   if(FracCheck($A)==0) { return NULL; }
   else
      {
         $i=0;
         $len=strlen($A)-1;
         while($A[$i]!="/" && $i<=$len)
            {
                $Numer=$Numer.$A[$i];
                $i++;
            }
         return $Numer;
      }
}


function FracDenom($A)
 
{
    if(FracCheck($A)==0) { return NULL; }   
    else
        {
          $i=0; $len=strlen($A)-1;
          while($A[$i]!="/" && $i<=$len)
             {
                $i++;
             }
          if($i>$len) {  return 1; }
          else
              {
                  $i++;
                  while($i<=$len)
                    {
                         $Denom=$Denom.$A[$i];
                         $i++;
                    }
                return $Denom;
              }
        }
  }

[msu_math]

Sample Return Values:

FracNumer("-11/7");    Return value:  "-11"

FracNumer("28");    Return value:  "28"

FracDenom("28");    Return value:  "1"

FracDenom("5/7");    Return value:  "7"

FracNumer("-3/5/7");    Return value:  NULL   
         
      *Because "-3/5/7" is not a valid fraction. ("-3/5/7" contains more than one "/")

FracDenom("51/7k");    Return value:  NULL   

      *Because "51/7k" is not a valid fraction. ("51/7k" contains non-digit character "k")