Post dynamic checkbox ids with values - php

Question

Here is a form which contains dynamic checkbox retrieved from database table named "categories". All i am trying is to echo category id + name on a new page. I want all the selected categories with their ID's. the problem is the output shows the category names but it shows the last category id with each name.
Form
<form method="post" action="insert_try.php" enctype="multipart/form-data">
<label>Select categories</label>
<?php
$result = mysqli_query($con,"select * from categories");
if (mysqli_num_rows($result) > 0) {
while($row = mysqli_fetch_array($result)) {
?>
<br><input type="checkbox" name="categories_chk[]" value="<?= $row["cat_name"]; ?>"> <?= $row["cat_name"]; ?>
<input type="text" name="cat_chk_id" value="<?= $row["cat_id"]; ?>">
<?php
}
}
?>
<input type="submit" name="submit" value="Add">
</form>
insert_try.php
if(isset($_POST['submit'])) {
$cat_chk = $_POST['categories_chk'];
$cat_chk_id=$_POST['cat_chk_id'];
foreach ($cat_chk as $checkbox) {
echo $checkbox;
}
echo $cat_chk_id;

Answer 1

I don't know why you need this but in your case I would do this:
while($row = mysqli_fetch_array($result)) {?>
<br><input type="checkbox" name="categories_chk[<?= $row["cat_id"]; ?>]" value="<?= $row["cat_name"]; ?>"> <?= $row["cat_name"]; ?>
<?php
}
See, I set index of categories_chk as a category id.
If you print_r($_POST['categories_chk']) you will have a key=>value array where key is category id and value is it's name.
You can iterate over it kinda:
foreach ($_POST['categories_chk'] as $id => $name) {
echo 'Category id ' . $id . ' with name ' . $name;
}
Of course, I need to mention that $row["cat_id"] must be unique for such approach, otherwise you will have two same keys in array and the latter overwrites the previous one.