title: Combine certain values in one array with values in another array
body: <p>I would like to combine the values which contain the prefix <code>lt_</code> in <code>$url</code>  with the values in <code>$color</code> and create a new array <code>$new</code>. Both arrays <code>$url</code> and <code>$color</code> store values for the next 36 hours: </p>
  
  <pre><code>print_r($url);
  </code></pre>
  
  <p>outputs</p>
  
  <pre><code> Array(
       [0]  =&gt; "http://example.com/color/green.png",
       [1]  =&gt; "http://example.com/color/lt_green.png",
       [2]  =&gt; "http://example.com/color/lt_blue.png",
       [3]  =&gt; "http://example.com/color/blue.png",
       [4]  =&gt; "http://example.com/color/blue.png",
       [5]  =&gt; "http://example.com/color/yellow.png",
       ..
       [35] =&gt; "http://example.com/color/lt_blue.png",
       );
  </code></pre>
  
  <p>and</p>
  
  <pre><code>print_r($color);
  </code></pre>
  
  <p>outputs</p>
  
  <pre><code>Array(
       [0]  =&gt; "Green",
       [1]  =&gt; "Green",
       [2]  =&gt; "Blue",
       [3]  =&gt; "Blue",
       [4]  =&gt; "Blue",
       [5]  =&gt; "Yellow",
       ...
       [35] =&gt; "Blue",
       );
  </code></pre>
  
  <p>I have managed to find the string part <code>lt_</code> in <code>$url</code> and get the keys in <code>$new</code> but how can I add "Light" (or <code>lt_</code>) to the corresponding values in <code>$color</code> to populate <code>$new</code>?</p>
  
  <pre><code>$new = array(
       [0]  =&gt; "Green",
       [1]  =&gt; "Light Green",
       [2]  =&gt; "Light Blue",
       [3]  =&gt; "Blue",
       [4]  =&gt; "Blue",
       [5]  =&gt; "Yellow",
       ...
       [35] =&gt; "Light Blue",
   );
  </code></pre>
  
  <p>I have managed to create an array with only the keys which values contain <code>lt_</code>:</p>
  
  <pre><code>$lt = 'lt_';
  foreach($url as $key1=&gt;$value1)
  {
    foreach($color as $key2=&gt;$value2)
    {
        if (strpos($value1,$lt) !== false)
        {
            $new[$key1] = array();
        }
    }
  }
  </code></pre>