Loop to repeat the previous keys (3, 32, 321, ...)

Question

I’m trying to make a breadcrumb dynamic and need to make a loop to mount the link. At each loop, it needs to repeat the previous items, as in the example below the array and the output.

array( array( 'Bairro' , 'bairro' ) , array( 'Rua' , 'rua' ) )

<a href="bairro">Bairro</a>
<a href="bairro/rua">Rua</a>

What little I got was using unset to generate a new array. After this for to mount the repetition, i still need 2 more loops and reverse the order. A hell of a gambiarra.

foreach( $list as $i => $item ){
    $newlist[] = $list;
    unset( $list[$i] );
}

Answer 1

I believe that by accumulating the link in a variable you get the result you expect, for example:

$breadcrumbs = array( array( 'Bairro' , 'bairro' ) , array( 'Rua' , 'rua' ) );

foreach ( $breadcrumbs as $item ) {
    $link_acumulado .= $item[1] . '/';

    echo '<a href="' . trim( $link_acumulado, '/' ) . '">' . $item[0] . '</a>';
}

Exit:

<a href="bairro">Bairro</a>
<a href="bairro/rua">Rua</a>

Answer 2

I will leave another possibility, more complex and less performative than Márcio’s, but still valid.

If you transpose the original matrix will always have an array of two indices, one with the Labels and the other with the Breadcrumbs.

Combine the indexes into a new matrix (described here as $Breadcrumbs) and eternal:

$previous = NULL;

$last = key( array_slice( $breadcrumbs, -1, 1, TRUE ) );
$separator = ' » ';

foreach( $breadcrumbs as $label => $breadcrumb ) {

    $previous .= sprintf( '/%s', $breadcrumb );

    if( $label == $last ) $separator = NULL;

    printf( '<a href="%s">%s</a>%s', $previous, $label, $separator );
}