debx();      function debx()   {     $dkm   = 240; //貸款月數，20年就是240個月     $dkTotal = 10000; //貸款總額     $dknl  = 0.0515; //貸款年利率     $emTotal = $dkTotal * $dknl / 12 * pow(1 + $dknl / 12, $dkm) / (pow(1 + $dknl / 12, $dkm) - 1); //每月還款金額     $lxTotal = 0; //總利息     for ($i = 0; $i < $dkm; $i++) {       $lx   = $dkTotal * $dknl / 12;  //每月還款利息       $em   = $emTotal - $lx; //每月還款本金       echo "第" . ($i + 1) . "期", " 本金:", $em, " 利息:" . $lx, " 總額:" . $emTotal, "<br />";       $dkTotal = $dkTotal - $em;       $lxTotal = $lxTotal + $lx;     }     echo "總利息:" . $lxTotal;   }         function debj()   {     $dkm   = 240; //貸款月數，20年就是240個月     $dkTotal = 10000; //貸款總額     $dknl  = 0.0515; //貸款年利率           $em   = $dkTotal / $dkm; //每個月還款本金     $lxTotal = 0; //總利息     for ($i = 0; $i < $dkm; $i++) {       $lx   = $dkTotal * $dknl / 12; //每月還款利息       echo "第" . ($i + 1) . "期", " 本金:", $em, " 利息:" . $lx, " 總額:" . ($em + $lx), "<br />";       $dkTotal -= $em;       $lxTotal = $lxTotal + $lx;     }     echo "總利息:" . $lxTotal;   }         exit;