heredoc没有缩进或正常工作

Question

new to PHP. Just having some frustrating problems with heredoc, despite following the book to the letter on syntax. The below text isn't indented as it should be.

<?php

$text="Mike's";

echo <<<_END

<!--END is just like double quoteing a var..
You can use single/double quotes without having to escape them first; inside 
END. The last _END tag, has to be on the start of new line with nothing allowed
to procede it, not even whitespace-->

This is the $text 'first line'.

This is the $text 'second line'.

This is the $text 'third line'.
_END;
?>

Answer 1

Based on the presence of "<!--" - you are creating a html page.

You're looking at the wrong problem, heredocs don't modify whitespace - but html ignores it unless you specify otherwise. To confirm just look at the page source, it'll be what you are expecting.

If you want whitespace to be preserved - use a <pre> tag or more correctly use real markup

i.e.

<pre>
This
is
3 lines
<pre>

or

This<br>
is<br>
3 lines<br>

or

<p>This<p>
<p>is</p>
<p>3 line</p>

will all render on 3 lines.

w3 whitespace reference