foreach loop Undefined index: title - php

Question

I am trying to output the results of some blog posts using a foreach loop but I keep getting the error "Undefined index: title"
<?php foreach ($post as $post_item):?>
<div class="postDiv">
<h4><?php echo $post_item['title'];?></h4>
<p><?php echo $post_item['summary'];?></p>
</div>
<?php endforeach;?>
here is my array when calling var_dump($post)
array(4) {
["id"]=> array(5) {
[0]=> string(2) "15"
[1]=> string(2) "16"
[2]=> string(2) "17"
[3]=> string(2) "18"
[4]=> string(2) "19" }
["title"]=> array(5) {
[0]=> string(3) "234"
[1]=> string(2) "11"
[2]=> string(1) "2"
[3]=> string(3) "444"
[4]=> string(5) "title" }
["summary"]=> array(5) {
[0]=> string(3) "213"
[1]=> string(2) "11"
[2]=> string(1) "2"
[3]=> string(3) "444"
[4]=> string(7) "summary" }
["content"]=> array(5) {
[0]=> string(3) "234"
[1]=> string(1) "1"
[2]=> string(1) "2"
[3]=> string(3) "444"
[4]=> string(7) "content" } }
I am a noob at php and I am also using codeigniter if that makes a difference here (I dont think it should). If I use the following code I can print out the posts for the title only but this is not what I want as I want to add in more fields later
<?php foreach ($post['title] as $post_item):?>
<div class="postDiv">
<h4><?php echo $post_item;?></h4>
</div>
<?php endforeach;?>
Here is my final code that worked for me
<?php
foreach (array_reverse(array_keys($post["id"]), true) as $key):?>
<div class="postDiv">
<h4><?php echo $post['title'][$key];?></h4>
<p><?php echo $post['summary'][$key];?></p>
<p><?php echo $post['content'][$key];?></p>
<div style="float:right">
<p><?php echo anchor('admin/edit/'.$post['id'][$key],' [edit]');?></p>
<p><?php echo anchor('admin/delete/'.$post['id'][$key],' [delete]');?></p>
</div>
</div>
<?php endforeach;?>

Answer 1

Your array is somehow misaligned for your design.
<?php foreach (array_keys($post["id"]) as $key):?>
<div class="postDiv">
<h4><?php echo $post['title'][$key];?></h4>
<p><?php echo $post['summary'][$key];?></p>
</div>
<?php endforeach;?>

Answer 2

It looks like your post information is split across multiple array keys based on a numeric reference, so you can use that numeric key reference to access the sibling array keys which contain the rest of your data.
foreach($post['id'] as $key => $id) {
$title = $post['title'][$key];
$summary = $post['summary'][$key];
$content = $post['content'][$key];
}

Answer 3

Just for you understanding:
with foreach ($a as $k) you are iterating an array $a, and putting in each iteration, one first level element in $k.
So, in the first iteration,
$post_item will be
array(5) {
[0]=> string(2) "15"
[1]=> string(2) "16"
[2]=> string(2) "17"
[3]=> string(2) "18"
[4]=> string(2) "19" }
in the second, $post_item will be:
array(5) {
[0]=> string(3) "234"
[1]=> string(2) "11"
[2]=> string(1) "2"
[3]=> string(3) "444"
[4]=> string(5) "title" }
and so on.
I dont even think that this secodn level indexes, 0,1,2,3,4,5 has an specific meannig to you, and for sure, if you do that foreach( array_keys($post["id"]) ...) would be the same as just iterating from harcoded 0 to count($post), and if you iterate foreach( $post["id"] as $k) and then use $k as index to the other elements, that wouldnt work alos, since the values of id, are not the keys of any other elements. so you will get many undefined index warnings.
and also im not sure if the values, the right side of every element, are actually any kind of usefull information for you. So, we could find some tricks here to get the result that you want, but what you need to fix is one step before, when you create $post