This is valid syntax. Though you usually see the latter variant, it's just two syntaxes to express the same thing.

actually both are correct, so why do you think it has to be one, not the other?

Hi,

Thank you for your quick reply!

I know there are 2 syntaxes to express the same thing, but in this case, it doesn't work :(

I simply created a file and inserted the documentation code :

<?php

$juice = "apple";

echo "He drank some $juice juice.".PHP_EOL;
// Invalid. "s" is a valid character for a variable name, but the variable is $juice.
echo "He drank some juice made of $juices.";
// Valid. Explicitly specify the end of the variable name by enclosing it in braces:
echo "He drank some juice made of ${juice}s.";

Here's the result:

php -f index.php
He drank some apple juice.
PHP Notice:  Undefined variable: juices in index.php on line 7

Notice: Undefined variable: juices in index.php on line 7
He drank some juice made of .He drank some juice made of apples.%

I hope it will help you to check this documentation error.

Check line 7.  See https://3v4l.org/A1mQQ.

Yes, you are entirely right.

The problem is on line 7 that corresponds at :

echo "He drank some juice made of $juices.";

It's my fault, I don't know why but I thought the comments described the line above and not the line under :(