Create list per 4 records [duplicate] - php

Question

This question already has answers here:
display data in multiple columns
(3 answers)
Closed 8 years ago.
I am trying to create multi-list of records with 4 records per list without knowing how many records there are. However, I cannot figure out how to handle the math. I manually typed in $n == 5 || $n == 9 etc knowing it is stipud and cannot exactly solve the problem. Can anyone help me how to handle that. Also, the lists underneath works well only if the total number of records cannot be evenly divided by 4. If it can, it will create a blank list at the end.
$query = "SELECT * FROM `table` WHERE `field` = $whatever";
if ($result = $con->query($query)){
$n = 1
$row_cnt = $result->num_rows;
$total_lists = round($row_cnt / 4, 0);
$current_list = 1;
echo "<ul>List $current_list of $total_lists";
while ($row = $result->fetch_assoc()) {
echo "<li>$row['something']</li>";
if ($n == 5 || $n == 9 || $n == 13 || $n == 17 || $n == 21 || $n ==25 || $n ==29 || $n == 33 || $n == 37 || $n == 41 || $n == 45 || $n == 49 || $n == 53 || $n == 57 || $n == 61 || $n == 65 || $n == 69 || $n == 73 || $n == 77){
echo "</ul>";
$current_list = $current_list + 1;
echo "<ul>List $current_list of $total_lists";
}
$n = $n + 1;
}
echo "</ul>";
}
Thanks in advance for the help. :)
SOLVED:
$query = "SELECT * FROM `table` WHERE `field` = $whatever";
if ($result = $con->query($query)){
$n = 0
$row_cnt = $result->num_rows;
$total_lists = ceil($row_cnt / 4);
$current_list = 1;
echo "<ul>List $current_list of $total_lists";
while ($row = $result->fetch_assoc()) {
$n++;
echo "<li>$row['something']</li>";
if ($row_cnt > 4) {
if ($n % 4 === 0) {
echo "</ul>";
$current_list = $current_list + 1;
echo "<ul>List $current_list of $total_lists";
}
}
}
echo "</ul>";
}

Answer 1

You're actually not too far off track from what you might want to be doing, you just need to use one additional tool to accomplish it: the % or modulus operator.
The modulus operator will return the remainder of division problem:
$x = 5 % 2; // 1
Looking at your logic, your action needs to be taken when your incrementer ($n) minus 1 divided by 4 would have a remainder of 0:
if (($n - 1) % 4 === 0)
{
//your <ul> insertion could go here.
}
Here's a link to the PHP manual page discussing mathematical operators:
http://us1.php.net/manual/en/language.operators.arithmetic.php

Answer 2

Alternatively, you could use a simple array_chunk() on your db results. Provide the proper grouping (in this case by four's) to it and them loop them thru foreach. Consider this example:
// dummy data (values from db)
$values_from_db = array(
array('id' => 1, 'something' => 'list1'),
array('id' => 2, 'something' => 'list2'),
array('id' => 3, 'something' => 'list3'),
array('id' => 4, 'something' => 'list4'),
array('id' => 5, 'something' => 'list5'),
array('id' => 6, 'something' => 'list6'),
array('id' => 7, 'something' => 'list7'),
array('id' => 8, 'something' => 'list8'),
array('id' => 9, 'something' => 'list9'),
);
$values_from_db = array_chunk($values_from_db, 4); // group them by four's
?>
<?php foreach($values_from_db as $key => $value): ?>
<ul style="list-style-type: none;">
<?php foreach($value as $index => $element): ?>
<li><?php echo $element['id'].'.'.$element['something']; ?></li>
<?php endforeach; ?>
</ul>
<?php endforeach; ?>