Loop array foreach and add further array values per group?

Question

for each Example 1 caption and 3 occurrences for the source map

What am I doing wrong?

Images Array

$imgsArray = array(
  'image1-small.jpg', 'image1-medium.jpg', 'image1-large.jpg',
  'image2-small.jpg', 'image2-medium.jpg', 'image2-large.jpg',
  'image3-small.jpg', 'image3-medium.jpg', 'image3-large.jpg'
); // sometimes more pictures too

Captions Array

$imgCaption = array('Adam','Peter','Susi');

the code

foreach($imgsArray as $files => $img) {
  $first_char = substr($img,0,strpos($img,"-")); // delete from hyphen to the last string
  if ($first_char != $last_entry) {
  echo '<p>This is '.$imgCaption[$files];
  echo '<ul>';
    echo '<li>'.$first_char.'-small.jpg</li>';
    echo '<li>'.$first_char.'-medium.jpg</li>';
    echo '<li>'.$first_char.'-large.jpg</li>';
    echo '<li>'.$imgCaption[$files].'</li>';
  echo '</ul>';
  echo '<i>Ciao, '.$imgCaption[$files].'</i><br>---</p>';
  }
  $last_entry = $first_char;
}

unexpected

This is Adam

image1-small.jpg
image1-medium.jpg
image1-large.jpg
Adam

Ciao, Adam
---

This is Notice: Undefined offset: 3 in...

image2-small.jpg
image2-medium.jpg
image2-large.jpg
Notice: Undefined offset: 3 in...

Ciao, Notice: Undefined offset: 3 in...
---

This is Notice: Undefined offset: 3 in...
image3-small.jpg
image3-medium.jpg
image3-large.jpg
Notice: Undefined offset: 6 in...
Ciao, Notice: Undefined offset: 3 in...
---

expected

This is Adam

image1-small.jpg
image1-medium.jpg
image1-large.jpg
Adam

Ciao, Adam
---

This is Peter

image2-small.jpg
image2-medium.jpg
image2-large.jpg
Peter

Ciao, Peter
---

This is Susi

image3-small.jpg
image3-medium.jpg
image3-large.jpg
Susi

Ciao, Susi
---

Something just to check - why do you have all the values in $imgsArray and then ignore most of them and add what looks like the same extension in the loop? — Nigel Ren
– Nigel Ren, Commented Apr 11, 2020 at 7:53
I have simplified the question. the image groups are actually under <img> tags (depending on the resolution) and each image group also has caption — Cem Firat
– Cem Firat, Commented Apr 11, 2020 at 8:06

Nigel Ren · Accepted Answer · 2020-04-11 07:52:07Z

1

The problem is that using the index to the $imgsArray for the $imgCaption array isn't going to work.

The easy fix is to just keep track of how many times you put out the text and increment it each time ($textCount in this example) ...

$textCount = 0;
$last_entry = '';
foreach($imgsArray as $files => $img) {
    $first_char = substr($img,0,strpos($img,"-")); // delete from hyphen to the last string
    if ($first_char != $last_entry) {
        echo '<ul>';
        echo '<li>'.$first_char.'-small.jpg</li>';
        echo '<li>'.$first_char.'-medium.jpg</li>';
        echo '<li>'.$first_char.'-large.jpg</li>';
        echo '<li>'.$imgCaption[$textCount++].'</li>';
        echo '</ul>';
    }
    $last_entry = $first_char;
}

answered Apr 11, 2020 at 7:52

Nigel Ren

57.3k11 gold badges49 silver badges59 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Cem Firat Over a year ago

thank you, but to avoid abuses I took $imgArray names instead of numbers - $imgCaption = array('Adam','Peter','Susi');

Nigel Ren Over a year ago

OK, not sure what difference that makes, this code just move on to the next element in $imgCaption each time the name changes in $imgArray.

Cem Firat Over a year ago

You're right! Thank you for your answer. Best regards from Vienna

Cem Firat Over a year ago

I have simplified the question. the image groups are actually under <img> tags (depending on the resolution) and each image group also has caption

Nick · Accepted Answer · 2020-04-11 09:23:43Z

1

If you always have one caption for 3 images you might want to consider a numerically indexed loop:

$imgsArray = array(
  'image1-small.jpg', 'image1-medium.jpg', 'image1-large.jpg',
  'image2-small.jpg', 'image2-medium.jpg', 'image2-large.jpg',
  'image3-small.jpg', 'image3-medium.jpg', 'image3-large.jpg'
);

$imgCaption = array('Adam','Peter','Susi');

for ($i = 0; $i < count($imgCaption); $i++) {
    echo '<p>This is '.$imgCaption[$i];
    echo "<ul>\n";
    for ($j = 0; $j < 3; $j++) {
        echo '<li>' . $imgsArray[$i * 3 + $j] . "</li>\n";
    }
    echo "<li>{$imgCaption[$i]}</li>\n";
    echo "</ul>\n";
    echo '<i>Ciao, '.$imgCaption[$i].'</i><br>---</p>';
}

Output:

This is Adam

image1-small.jpg
image1-medium.jpg
image1-large.jpg
Adam

Ciao, Adam
---

This is Peter

image2-small.jpg
image2-medium.jpg
image2-large.jpg
Peter

Ciao, Peter
---

This is Susi

image3-small.jpg
image3-medium.jpg
image3-large.jpg
Susi

Ciao, Susi
---

Demo on 3v4l.org

edited Apr 11, 2020 at 9:23

answered Apr 11, 2020 at 8:02

Nick

147k23 gold badges67 silver badges106 bronze badges

4 Comments

Cem Firat Over a year ago

I have simplified the question. the image groups are actually under <img> tags (depending on the resolution) and each image group also has caption

Nick Over a year ago

We can only answer the question you have posted. That calls for unordered lists, which this (and Nigel's answer) produce. I've updated my answer to reflect your expected output

Cem Firat Over a year ago

Thank you for your answer. Best regards from Vienna!

Nick Over a year ago

@CemFirat not sure what you mean by that. This code is simply outputting the image names that exist in the array. I think it would be good if you updated the question to better reflect your actual code, it would make it a lot easier to give you a solution that you can then make work in your environment.

Collectives™ on Stack Overflow

Loop array foreach and add further array values per group?

for each Example 1 caption and 3 occurrences for the source map

2 Answers 2

4 Comments

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

for each Example 1 caption and 3 occurrences for the source map

2 Answers 2

4 Comments

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related