php unique/group associative array
<p>I would like to remove duplicates for the following array. I want to group by the first value and then rebuild the index.</p>

<p>ie</p>

<pre><code>Array
(
    [0] =&gt; Array
        (
            [title] =&gt; California
            [state_id] =&gt; 1
        )

    [1] =&gt; Array
        (
            [title] =&gt; California
            [state_id] =&gt; 1
        )

    [2] =&gt; Array
        (
            [title] =&gt; New Mexico
            [state_id] =&gt; 2
        )

    [3] =&gt; Array
        (
            [title] =&gt; Washington
            [state_id] =&gt; 3
        )

    [4] =&gt; Array
        (
            [title] =&gt; Montana
            [state_id] =&gt; 4
        )

    [5] =&gt; Array
        (
            [title] =&gt; Montana
            [state_id] =&gt; 4
        )
)
</code></pre>

<p>To</p>

<pre><code>Array
(
    [0] =&gt; Array
        (
            [title] =&gt; California
            [state_id] =&gt; 1
        )

[2] =&gt; Array
    (
        [title] =&gt; New Mexico
        [state_id] =&gt; 2
    )

[3] =&gt; Array
    (
        [title] =&gt; Washington
        [state_id] =&gt; 3
    )

[4] =&gt; Array
    (
        [title] =&gt; Montana
        [state_id] =&gt; 4
    )

)
</code></pre>

<p>and rebuild key</p>

<pre><code>Array
(
    [0] =&gt; Array
        (
            [title] =&gt; California
            [state_id] =&gt; 1
        )

    [1] =&gt; Array
        (
            [title] =&gt; New Mexico
            [state_id] =&gt; 2
        )

    [2] =&gt; Array
        (
            [title] =&gt; Washington
            [state_id] =&gt; 3
        )

    [3] =&gt; Array
        (
            [title] =&gt; Montana
            [state_id] =&gt; 4
        )

)
</code></pre>
