PHP multidimensional array combine
<p>I am hoping to find help how to get to such structure:</p>

<pre><code>[pad] =&gt; Array
    (
        [padi] =&gt; Array
            (
                [Date] =&gt; 2016-01-01
                [Val] =&gt; 1
                [Premium] =&gt; 100
            )
        [padi] =&gt; Array
            (
                [Date] =&gt; 2016-04-01
                [Val] =&gt; 1
                [Premium] =&gt; 200
            )
        [padi] =&gt; Array
            (
                [Date] =&gt; 2016-07-01
                [Val] =&gt; 1
                [Premium] =&gt; 300
            )
        [padi] =&gt; Array
            (
                [Date] =&gt; 2016-11-01
                [Val] =&gt; 1
                [Premium] =&gt; 400
            )

    )
</code></pre>

<p>I have 4 variables:</p>

<pre><code>$p1 = array('padi' =&gt;
                    array('Date' =&gt; $Date_0, 'Val' =&gt; $Val, 'padiPremium' =&gt; $padiPremium_0));
$p2 = array('padi' =&gt;
                    array('Date' =&gt; $Date_1, 'Val' =&gt; $Val, 'padiPremium' =&gt; $padiPremium_1));
$p3 = array('padi' =&gt;
                    array('Date' =&gt; $Date_1, 'Val' =&gt; $Val, 'padiPremium' =&gt; $padiPremium_1));
$p4 = array('padi' =&gt;
                    array('Date' =&gt; $Date_1, 'Val' =&gt; $Val, 'padiPremium' =&gt; $padiPremium_1));
</code></pre>

<p>I have already tried with <code>array_push</code>, <code>array_merge</code> and <code>array_combine</code> and that didn't work for me at all or just my approach was wrong.
I would be gratefull to any suggestions !</p>