问题
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
回答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.
回答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.
回答3:
Heredoc is very finicky. Make sure there are no spaces after your initial EOD. And the final EOD; must be on it's own line, with no spaces before it, and nothing else on that line. It's those spaces that give most people trouble.
And the quotes around 'EOD' aren't necessary.
回答4:
It took me sometime to master heredoc and nowdoc. Heredoc is a very tricky business. Here is the trick, the terminators should always be on singles lines except for the beginning terminator where you can add a variable or echo the string out and dont forget its is also not allowed to indent the closing tag
<?php
$string = <<<EXP // There should be nothing following this terminator <<<EXP
You string goes here and it can include commas, quotes etc
EXP;// This should be on a single line without anything else. Hit enter to make it contain this line, even if there is nothing to write, still hit enter, because it should be the master of this line
$string = <<<EXP2
I am a developer.
EXP2// Hit enter, please always do
echo $string // Works perfect
?>
回答5:
One more thing: the closing tag is not "whatever you give", it must be a valid identifier with alphanumerics only (underscores are fine), if you give it any other character you'll be sorely disappointed.
Look:
$str = <<<'HEY WHAT THE HECK'
This will not work
and doesn't help you understand why
HEY WHAT THE HECK
;
PHP will give you a syntax error. Now if you remove the spaces,
$str = <<<'HEYWHATTHEHECK'
Suddenly it's all peaches & cream
HEYWHATTHEHECK
;
(I just tried to use some UUID to make sure it won't happen inside the string. After 25 minutes of swearing I finally realized this.)
Happy nowdocking!
来源：https://stackoverflow.com/questions/16745654/why-do-these-heredoc-and-nowdoc-cause-errors