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: 我想知道在以下上下文中使用花括号的优点是什么：

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

is over the following: 超过以下：

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

In particular, how is it that the braces resolve any possible ambiguity in this case (or similar cases)? 特别是，在这种情况下（或类似情况），大括号如何解决任何可能的歧义？

Answer 1

Second example will not be parsed. 第二个例子不会被解析。 So first is better:) 所以首先是更好的:)

Anyway, I prefer to use 无论如何，我更喜欢使用

echo "Hello" . $world["foo"] . ".\n";

Because it is more easy to read to me. 因为它更容易给我读。

Besides, there is another way: 此外，还有另一种方式：

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

There no resaons to use one or another. 没有任何反复使用这一个或另一个。 you what you(or your team) like. 你是你（或你的团队）喜欢什么。

Answer 2

See the other answers for the "echo" explanation, but if you're using heredoc, such as the following: 请参阅“echo”解释的其他答案，但如果您正在使用heredoc，例如以下内容：

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

You need the curly braces to properly use the associative array. 您需要花括号来正确使用关联数组。