PHP循环 - 无法为每个组重复关闭标记[关闭]

I can't work out where I'm going wrong here I'm afraid.

I'm trying to loop through each unique group (each unique layout - let's say theres 'short', 'medium' and 'long' in this dataset) and for each item in that group to print it within the items section.

I've got to the following code, but the problem is the footers are only printing once at the end of all of the code - I need them to print after the items in each section.

<?php $seriesgroup = ''; if (mysqli_num_rows($result3) > 0) {while($row = mysqli_fetch_assoc($result3)) {
if($row['layout'] != $seriesgroup) {  ?>

    <!-- Print group headers -->

<?php $seriesgroup = $row['layout']; } ?>

        <!-- Print group items -->

<?php } ?>

    <!-- Print footers -->

<?php } ?>

There is a confusion in your mind about how HTML and PHP interact. The way to do this is to use the statement echo from inside the PHP part of your code.

Edit: Try this new version. The code is cleaner:

<?php 
  $previousrow = array ('layout' => ''); 

  if (mysqli_num_rows($result3) > 0) {
    while($row = mysqli_fetch_assoc($result3)) {
      if($row['layout'] != $previousrow['layout']) { // new group
        if ($previousrow['layout'] !=== '') { // not on first row
          print_footers ($previousrow);
        }
        print_headers ($row);
      } 
      print_group_items ($row);
      $previousrow = $row;
    }
    print_footers ($previousrow);
  } 

function print_group_items ($this_row) {
  echo "  <!-- Print group items -->"
; // will depend on $this_row
}

function print_headers ($this_row) {
  echo "<!-- Print headers -->
"; // will depend on $this_row
}

function print_footers ($this_row) {
  echo "<!-- Print footers -->
"; // will depend on $this_row
}
?>

This was the previous version and wasn't correct, due to a.o. a tipo in the line containing print_footers; without ().

<?php 
  $seriesgroup = ''; 
  $firstgroup = 1;

  if (mysqli_num_rows($result3) > 0) {
    while($row = mysqli_fetch_assoc($result3)) {
      if($row['layout'] != $seriesgroup) { 
        if (! $firstgroup) {
          print_footers ();
          $firstgroup = 0;
        }
        print_headers ();
        $seriesgroup = $row['layout']; 
      } 
      print_group_items ($row);
    }
    print_footers;
  } 

function print_group_items ($this_row) {
  echo "  <!-- Print group items -->"
; // will depend on $this_row
}

function print_headers () {
  echo "<!-- Print headers -->
";
}

function print_footers () {
  echo "<!-- Print footers -->
";
}
?>

The way you are doing this will require you to print the group footer both near the top of the loop if it's not the first one...and at the end of the loop, assuming there was a row.

<?php $seriesgroup = ''; if (mysqli_num_rows($result3) > 0) {while($row = mysqli_fetch_assoc($result3)) {
if($row['layout'] != $seriesgroup) {  ?>

Print group footer if seriesgroup isn't blank here

<!-- Print group headers -->

<?php $seriesgroup = $row['layout']; } ?>

    <!-- Print group items -->

<?php } ?>

<!-- Print footers -->

<?php } ?>

Print group footer again if series group isn't blank