Calculating golf score against course par

Question

This PHP script will translate shots on 18 holes to a total under par or E which is 0.

$course = array(0, 4, 5, 4, 3, 5, 3, 4, 4, 4, 4, 4, 4, 4, 3, 5, 3, 4, 5);

if ($totalpar == 0) {
    $score = 'E';
    $played = 0;
} else {
if(!empty($h1)) {
 $h1score = $course[1] - $h1; 
} else {
 $h1score = 0;
 }
if (!empty($h2)) {
 $h2score = $course[2]- $h2; 
} else {
 $h2score = 0;
 }
if (!empty($h3)) {
 $h3score = $course[3] - $h3; 
} else {
 $h3score = 0;
 }
if (!empty($h4)) {
 $h4score = $course[4] - $h4; 
} else {
 $h4score = 0;
 }
if (!empty($h5)) {
 $h5score = $course[5] - $h5; 
} else {
 $h5score = 0;
 }
if (!empty($h6)) {
 $h6score = $course[6] - $h6; 
} else {
 $h6score = 0;
 }
if (!empty($h7)) {
 $h7score = $course[7] - $h7; 
} else {
 $h7score = 0;
 }
if (!empty($h8)) {
 $h8score = $course[8] - $h8; 
} else {
 $h8score = 0;
 }
if (!empty($h9)) {
 $h9score = $course[9] - $h9; 
} else {
 $h9score = 0;
 } 
if (!empty($h10)) {
 $h10score = $course[10] - $h10; 
} else {
 $h10score = 0;
 }
if (!empty($h11)) {
 $h11score = $course[11] - $h11; 
} else {
 $h11score = 0;
 } 
if (!empty($h12)) {
 $h12score = $course[12] - $h12; 
} else {
 $h12score = 0;
 }
if(!empty($h13)) {
 $h13score = $course[13] - $h13; 
} else {
 $h13score = 0;
 }
if(!empty($h14)) {
 $h14score = $course[14] - $h14; 
} else {
 $h14score = 0;
 }
if (!empty($h15)) {
 $h15score = $course[15] - $h15; 
} else {
 $h15score = 0;
 }
 if(!empty($h16)) {
 $h16score = $course[16] - $h16; 
}else {
 $h16score = 0;
 }
if(!empty($h17)) {
 $h17score = $course[17] - $h17; 
}else {
 $h17score = 0;
 }

if(!empty($h18)) {
 $h18score = $course[18] - $h18; 
}else {
 $h18score = 0;
 }
}

$scoresum = ($h1score + $h2score + $h3score + $h4score + $h5score + $h6score + $h7score + $h8score + $h9score + $h10score + $h11score + $h12score + $h13score + $h14score + $h15score + $h16score + $h17score + $h18score) * -1;

if ($scoresum != 0) {
    $score = $scoresum;
}
else {
    $score = 'E';
}

Answer 1

The big thing worth mentioning here is: Use an array for your scores.

The instant you do that, the code size shrinks dramatically.

$course = array(0, 4, 5, 4, 3, 5, 3, 4, 4, 4, 4, 4, 4, 4, 3, 5, 3, 4, 5);
$scores = array();

// $shots is your array of scores.  $shots[1] is the first hole, $shots[2] the second,
// etc.  If you remove the 0 at the beginning of `$course`, then $scores[0] will be
// the first, $scores[1] the second, etc, which is how arrays often look.  But with
// the zero, you can use the hole number as array index -- which might be more useful
// if these numbers are coming from an HTML form.

foreach ($course as $hole => $par) {
    if (!empty($shots[$hole])) {
        $scores[$hole] = $par - $shots[$hole];
    }
}

$scoresum = array_sum($scores);

if ($scoresum != 0) {
    $score = $scoresum;
}
else {
    $score = 'E';
}

But you could do even better than that, if you don't need those intermediate scores.

$course = array(0, 4, 5, 4, 3, 5, 3, 4, 4, 4, 4, 4, 4, 4, 3, 5, 3, 4, 5);
$score = 0;

foreach ($shots as $hole => $total) {
    if (!empty($total)) {
        $score += $course[$hole] - $total;
    }
}

if (empty($score)) $score = 'E';

---

And because this seems uncommon knowledge, and will simplify your life if these values are indeed from a form, you can get PHP to build your array for you by giving your inputs arrayish names. Like so:

<form>
    <input type="text" name="shots[1]">
    <input type="text" name="shots[2]">
    <input type="text" name="shots[3]">
    <input type="text" name="shots[4]">
    <input type="text" name="shots[5]">
 </form>

(You can even leave out the index, if you don't mind the auto-number indexes PHP does.)

When this form is submitted, $_POST['shots'] will be an array of all the inputs. Do something like:

$shots = array_map('intval', $_POST['shots']);

and you have an array containing the score entered for each hole (or 0 if the entered value didn't make sense as a number).

Answer 2

Instead of having 18 variables $h1 ... $h18 and $h1score ... $h18score, you should have arrays and do the calculation in loops.

Also, what is $played ? It is mentioned once, and seems to have no purpose.