How to print 2d php array with header

Question

How can I generate header for printed 2d array in php?

So my array look like this:

$tab=array(
    array(0,1,2,3),
    array(1,2,3,4),
    array(2,3,4,5)
)

This code:

foreach ($tab as $key => $row){
    echo '<b>o<sub>'.($key+1).'</sub></b> ';
    foreach ($row as $item) {
        echo $item.' ';
    }
    echo '<br>';
}

Print this:

0 1 2 3 0 1 2 3
1 2 3 4 1 2 3 4
2 3 4 5 2 3 4 5

But I need this:

0 1 2 3 0 1 2 3
1 2 3 4 1 2 3 4
2 3 4 5 2 3 4 5

Where lenght of rows may be diferent and last column always must be

Thanks for help

Answer 1

You can check if this is the first iteration in the first foreach and if so, add the first line.

foreach ($tab as $key => $row) {

    // If first iteration, add the header
    if ($key === 0)
    {
        foreach ($row as $i => $item)
        {
            // Last header must be 'd'
            if ($i === count($row) - 1)
                echo '<b>d</b>';
            else
                echo '<b>a<sub>' . ($i + 1) . '</sub></b> ';
        }

        echo '<br />';
    }

    // Add the current row
    echo '<b>o<sub>' . ($key + 1) . '</sub></b> ';
    foreach ($row as $item) {
        echo $item . ' ';
    }
    echo '<br />';

}

Answer 2

If the first row is a static row, then you can simply print it using echo function at first.

But if its a dynamic tab as well, then you can use the following code:

$count = count($tab[0]);
for($i = 1; $i <= $count; $i++)
{
    if($i != $count) echo '<b>a<sub>' . ($i + 1) . '</sub></b> ';
    else echo '<b>d</b> ';
}

foreach ($tab as $key => $row){
    echo '<b>o<sub>'.($key+1).'</sub></b> ';
    foreach ($row as $item) {
        echo $item.' ';
    }
    echo '<br>';
}

Answer 3

You can try this, except use <table> or <div> to align your elements.

foreach ($tab[0] as $key => $item)
    echo $key === 0 ? title('  ', ' ') : title('a', $key);

echo title('d', '') . '<br>';

function title(string $letter, string $index)
{
    return "<b>{$letter}<sub>{$index}</sub></b>";
}