Formatting php array to a tree like structure

Question

I have the following array:

$array = [
    1 => [
        'categoryName'=>'Main One',
        'title'=>'Title one',
        'date'=>'2019-09-01',
        'score'=>2500
    ],
    2 => [
        'categoryName'=>'Main One',
        'title'=>'Title two',
        'date'=>'2019-09-02',
        'score'=>3000
    ],
    3 => [
        'categoryName'=>'Main Two',
        'title'=>'Other title',
        'date'=>'2019-09-02',
        'score'=>2100
    ],
    4 => [
        'categoryName'=>'Main Three',
        'title'=>'Other title',
        'date'=>'2019-09-05',
        'score'=>200
    ],
    5 => [
        'categoryName'=>'Main Three',
        'title'=>'Other topic',
        'date'=>'2019-09-02',
        'score'=>1000
    ]
];

So if I run a foreach loop on it:

$html = '';
$html = '<table>';
foreach($array as $row){
    $html .= '<tr>';
    $html .= '<td>'.$row['categoryName'].'</td>';
    $html .= '<td>'.$row['title'].'</td>';
    $html .= '<td>'.$row['date'].'</td>';
    $html .= '<td>'.$row['score'].'</td>';
    $html .= '<tr>';
}
$html .='</table>';
echo $html;

This gives me the following output:

<table border=1>
<tbody>
<tr>
<td>Main One</td>
<td>Title one</td>
<td>2019-09-01</td>
<td>2500</td>
</tr>
<tr>
<td>Main One</td>
<td>Title two</td>
<td>2019-09-02</td>
<td>3000</td>
</tr>
<tr>
<td>Main Two</td>
<td>Other title</td>
<td>2019-09-02</td>
<td>2100</td>
</tr>
<tr>
<td>Main Three</td>
<td>Other title</td>
<td>2019-09-05</td>
<td>200</td>
</tr>
<tr>
<td>Main Three</td>
<td>Other topic</td>
<td>2019-09-02</td>
<td>1000</td>
</tr>
</tbody>
</table>

But I want the output in this format.

<table border=1>
  <tbody>
    <tr>
      <td colspan="2">Main One</td>
    </tr>
    <tr>
      <td>2019-09-01</td>
      <td>Title One</td>
      <td>2500</td>
    </tr>
    <tr>
      <td>2019-09-02</td>
      <td>Title Two</td>
      <td>3000</td>
    </tr>
    <tr>
      <td colspan="2">Main Two</td>
    </tr>
    <tr>
      <td>2019-09-02</td>
      <td>Other title</td>
      <td>2100</td>
    </tr>
    <tr>
      <td colspan="2">Main Three</td>
    </tr>
    <tr>
      <td>2019-09-05</td>
      <td>Other Title</td>
      <td>200</td>
    </tr>
    <tr>
      <td>2019-09-02</td>
      <td>Other topic</td>
      <td>1000</td>
    </tr>
  </tbody>
</table>

I could not get my head around on how to do it inside the foreach loop. What I did try:

 $prevmain = "";
 foreach($array as $row):
    $currentMain = $row['categoryName'];
    if($currentMain!=$prevMain){
       $html .='<tr>
                <td colspan="2">'.$row['currentMain'].'</td>
                <td></td>
               </tr>';
    } else{
       //Here I miss data for the first loop
       $html .='<tr>
                <td>'.$row['date].'</td>
                <td>'.$row['title'].'</td>
                <td>'.$row['score].'</td>
               </tr>';
     }
    $prevmain = $row['categoryName'];        
 endforeach;

As you can see from my attempt code, I miss one row for each loop of the main category. Can anyone help me?

The fact that the “main” value changed between the previous and the current item, does not mean that the data for the current item does not need to get printed at all - but you made printing it the else branch in your code. — 04FS
– 04FS, Commented Nov 1, 2019 at 12:22
(Btw., that will of course only work if those main values can occur two times at most. If that’s not the case, and it could be more, you’d need a more dynamic solution to figure out the correct colspan value to begin with.) — 04FS
– 04FS, Commented Nov 1, 2019 at 12:23
@04FS, thanks for the comment. It's just my attempted code. Please have a look at the expected output table in the question. — Hanner
– Hanner, Commented Nov 1, 2019 at 12:37
I don’t need to have a second look, I understood what you want already. That’s why I tried to give you an explanation of what you are currently doing wrong … Did you have trouble understanding what I was trying to say, or …? — 04FS
– 04FS, Commented Nov 1, 2019 at 12:51

The fourth bird · Accepted Answer · 2019-11-01 12:45:33Z

I think you don't need the else and only add the colspan part when the $prevMain and $currentMain are different.

$prevMain = "";
$currentMain = "";
$html = "";
foreach($array as $row):
    $currentMain = $row["categoryName"];
    if($currentMain !== $prevMain) {
        $prevMain = $row["categoryName"];
        $html .= '<tr>' .
            '<td colspan="2">' . $row['categoryName'] . '</td>' .
            '<td></td>' .
            '</tr>';
    }
    $html .='<tr>'.
            '<td>'.$row['date'] .'</td>'.
            '<td>'.$row['title'].'</td>'.
            '<td>'.$row['score'] . '</td>'.
           '</tr>';
endforeach;

echo $html;

See a php demo

Note that I have renamed $prevmain to $prevMain

After formatting the table row structure output will look like:

<tr>
    <td colspan="2">Main One</td>
    <td></td>
</tr>
<tr>
    <td>2019-09-01</td>
    <td>Title one</td>
    <td>2500</td>
</tr>
<tr>
    <td>2019-09-02</td>
    <td>Title two</td>
    <td>3000</td>
</tr>
<tr>
    <td colspan="2">Main Two</td>
    <td></td>
</tr>
<tr>
    <td>2019-09-02</td>
    <td>Other title</td>
    <td>2100</td>
</tr>
<tr>
    <td colspan="2">Main Three</td>
    <td></td>
</tr>
<tr>
    <td>2019-09-05</td>
    <td>Other title</td>
    <td>200</td>
</tr>
<tr>
    <td>2019-09-02</td>
    <td>Other topic</td>
    <td>1000</td>
</tr>

Ahmed Ali · Accepted Answer · 2019-11-01 12:47:11Z

0

Update your foreach with this:

$html = '';
$html = '<table>';
foreach($array as $row){
    $html .= '<tr>';
    $html .= '<td colspan="2">'.$row["currentMain"].'</td>';
    $html .= '<td></td>';
    $html .= '</tr>'
    $html .= '<tr>';
    $html .= '<td>'.$row['categoryName'].'</td>';
    $html .= '<td>'.$row['title'].'</td>';
    $html .= '<td>'.$row['date'].'</td>';
    $html .= '<td>'.$row['score'].'</td>';
    $html .= '</tr>';
}
$html .='</table>';
echo $html;

edited Nov 1, 2019 at 12:47

answered Nov 1, 2019 at 12:24

Ahmed Ali

1,96116 silver badges32 bronze badges

3 Comments

Hanner Over a year ago

Please look at the expected output table in the question.

Hanner Over a year ago

<table><tr><td colspan="2">Main One</td></tr><tr><td>Main One</td><td>Title one</td><td>2019-09-01</td><td>2500</td><tr><tr><td colspan="2">Main One</td></tr><tr><td>Main One</td><td>Title two</td><td>2019-09-02</td><td>3000</td><tr><tr><td colspan="2">Main Two</td></tr><tr><td>Main Two</td><td>Other title</td><td>2019-09-02</td><td>2100</td><tr><tr><td colspan="2">Main Three</td></tr><tr><td>Main Three</td><td>Other title</td><td>2019-09-05</td><td>200</td><tr><tr><td colspan="2">Main Three</td></tr><tr><td>Main Three</td><td>Other topic</td><td>2019-09-02</td><td>1000</td><tr></table>

Hanner Over a year ago

Also there is some syntax error. If you compare with my expected output. You may see the difference.

Andriy Budzinskyy · Accepted Answer · 2019-11-01 15:51:18Z

0

This is a multidimensional array. You can use key in your foreach loop:

foreach($array as $key => $row) {
   echo $row['categoryName']; ....
}

edited Nov 1, 2019 at 15:51

Andriy Budzinskyy

2,00125 silver badges30 bronze badges

answered Nov 1, 2019 at 15:42

Љубиша Ивановић

849 bronze badges

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