How to create a nested array out of an array in PHP

Question 1

Say, we have an array: array(1,2,3,4,...) And I want to convert it to:

array(
    1=>array(
        2=>array(
            3=>array(
                4=>array()
            )
        )
    )
)

Can anybody help?
Thanks

EDIT It would be good to have the solution with iterations.

Question 2

$x = count($array) - 1;
$temp = array();
for($i = $x; $i >= 0; $i--)
{
    $temp = array($array[$i] => $temp);
}

Question 3

function parameterize_array($array) {
    $out = array();
    foreach($array as $key => $value)
        $out[] = "$key=$value";
    return $out;
}

Question 4

The following snippet should do the trick, adapted from some PHP Doctrine code I found on the web :

function toHierarchy($collection)
{
        // Trees mapped
        $trees = array();
        $l = 0;

        if (count($collection) > 0) {
                // Node Stack. Used to help building the hierarchy
                $stack = array();

                foreach ($collection as $node) {
                        $item = $node;
                        $item['children'] = array();

                        // Number of stack items
                        $l = count($stack);

                        // Check if we're dealing with different levels
                        while($l > 0 && $stack[$l - 1]['depth'] >= $item['depth']) {
                                array_pop($stack);
                                $l--;
                        }

                        // Stack is empty (we are inspecting the root)
                        if ($l == 0) {
                                // Assigning the root node
                                $i = count($trees);
                                $trees[$i] = $item;
                                $stack[] = & $trees[$i];
                        } else {
                                // Add node to parent
                                $i = count($stack[$l - 1]['children']);
                                $stack[$l - 1]['children'][$i] = $item;
                                $stack[] = & $stack[$l - 1]['children'][$i];
                        }
                }
        }

        return $trees;
}

Question 5

You're missing only one important piece: when you make the recursive call to formatHtml() you're not actually including the returned content anywhere! Append it to $var and you should get much better results:

function formatHtml($array) {
    $var = '<div>';

    foreach ($array as $k => $v) {

            if (is_array($v['children']) && !empty($v['children'])) {
                $var .= formatHtml($v['children']);
            }
            else {
                $var .= $v['cid'];
            }
    }

    $var.= '</div>';

    return $var;
}

Question 6

You can put shared Angular components and modules into a separate npm package and use this package as a dependency for other projects. In order to reference your npm package (I assume it's not hosted at npmjs.com) you can specify a git repository or local path. Here is an example of package.json

{
  "name": "foo",
  "version": "0.0.0",
  "dependencies": {
    "my_git_package": "git+ssh://[email protected]/project.git#commit-ish",
    "my_local_package": "file:../foo/bar"
  }
}

Take a look at dependencies section here https://docs.npmjs.com/files/package.json

How to create a nested array out of an array in PHP

Answers

php,arrays,nested,iteration

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