Check if input field value exist in array, if so return to page with an error

Question

I have a form where user insert their names, once they submit the form, the page should check if the name provided already exists, if so, should return with an error, other wise

Answer 1

Just make use of a multi-level break statement and come out of the loop.

Something like

if (count($keys)>0)
    {
        // Add the key to the temp array so its not found again:
        $temp[] = $key;
        // Do something...
        echo '
Name already used';  
        break 3;                      
    }