PHP在带有花括号的字符串中嵌入数组元素

Question

I would like to know what the advantage of using curly braces is in the following context:

$world["foo"] = "Foo World!";
echo "Hello, {$world["foo"]}.
";

is over the following:

$world["foo"] = "Foo World!";
echo "Hello, $world["foo"].
";

In particular, how is it that the braces resolve any possible ambiguity in this case (or similar cases)?

Answer 1

See the other answers for the "echo" explanation, but if you're using heredoc, such as the following:

echo <<<EOHTML
<td>{$entity['name']}</td>
EOHTML;

You need the curly braces to properly use the associative array.