Why do these Heredoc and Nowdoc cause errors?

Question

I've already found some solutions, but can't know what happened...

Example 1:

<?php

echo <<< EOD
test
EOD;

Example 2:

<?php

echo <<< 'EOD'
test
EOD;

Output 1,2:

PHP Parse error:  syntax error, unexpected end of file, expecting variable (T_VARIABLE) or heredoc end (T_END_HEREDOC) or ${ (T_DOLLAR_OPEN_CURLY_BRACES) or {$ (T_CURLY_OPEN)

Example 3:

<?php

echo <<< EOD
test
EOD;

?>

Example 4:

<?php

echo <<< 'EOD'
test
EOD;

?>

Example 5:

<?php

echo <<< EOD
test
EOD;
'dummy';

Example 6:

<?php

echo <<< 'EOD'
test
EOD;
'dummy';

Output 3,4,5,6:

test

Answer 1

You probably have spaces after the terminator in your first two examples, e.g.

EOD;[space]

With this:

<?php
echo <<<EOL
test
EOL;[space]

I get your error message, but WITHOUT the space, there's no error. And that's true whether there's a closing ?> or not.

Answer 2

The closing delimiter must start on the first column, no spaces nor tabs allowed in front of it. Be aware that things are changing in 5.5 and 5.6

'EOD' is equivalent to echo ' ',
"EOD" is equivalent to echo " " about variable substitutions.

The closing delimiter doesn't take any single of double quotes.