Heredocs - Using same name twice? Why name them at all?

Question

Toying with heredocs in PHP, I realized the name of the heredoc does not have to be unique. Thus:

$a = <<<EOD
Some string
EOD;

$b = <<<EOD
A different string
EOD;

is correct and behaves exactly as you would expect.

Is this bad practice for any reason? Why does a heredoc need a name/label (EOD above) at all, since you can't reference it by the name?

Answer 1

You don't reference it as such, but it acts as an identifier to indicate the end of the heredoc. e.g.

$a = <<<EOD
EOA
EOB
EOC
EOD;

Answer 2

What if the string you're specifying contains EOD?

You can select the identifier to avoid conflicts with the chunk of text you're using as a string.

Answer 3

One benefit is that editors like vim can apply syntax highlighting to heredocs named with HTML, EOHTML, EOSQL, EOJAVASCRIPT making them much prettier to work with...

$html = <<<EOHTML

<p class="foo">foo</em>

EOHTML;

$sql = <<<EOSQL

SELECT DISTINCT(name) FROM foo ORDER BY bar;

EOSQL;

$js = <<<EOJAVASCRIPT

foo = { bar: 'bar'; }

EOJAVASCRIPT;