PHP foreach文でキーと値を取得

<?php
$test_array = array(
"aaa" => "A", "bbb" => "B", "ccc" => "C", "ddd" => "D", "eee" => "E",
"fff" => "F", "ggg" => "G", "hhh" => "H", "iii" => "I", "jjj" => "J"
);

foreach($test_array as $a => $b){
print $a."=>".$b."
";
}