PHP file_put_contents or fwrite ' and " characters

Hey guys, how do I write " and ' characters when I'm doing it via PHP eg

<?php
开发者_如何学运维$newFile = "<?php echo 'quote: "hello world"'; ?>"
file_put_contents('index.php', $newFile);
 ?>

Thanks

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\ is used to 'escape' things.

$newfile = "<?php echo 'quote: \"hello world\"'; ?>";

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You can only use one sort of quotes in a string literal. If another quote is to appear within the literal it needs to be escaped by a \

$newFile = "<?php echo 'quote: \"hello world\"'; ?>";
file_put_contents('index.php', $newFile);

---

$newFile = "<?php echo 'quote: \"hello world\"'; ?>"

Read this Strings manual.