Foreach and if broken

i have this code, and it still worked properly while...

$out_1 = array('284','345','456','284');
$a1 = '<img src="';
$a2 = '"/>';
$i = 0;

foreach ( $out_1 as $ar_1 ) {
    if  ($out_3[$i] == 284)
        echo $a1.$out_2[$i].$a2;
    { 
    $i++;
    }
}

?>

see below, $aaa it is example variable. (string or number).

foreach ( $out_1 as $ar_1 ) {
    if  ($out_3[$i] == 284)
        echo $aaa;

    echo $a1.$out_2[$i].$a2;
    {
    $i++;
    }
}
?>

And now this code not understand my IF construction. Why? Please help!