Escape " character in php with echo [duplicate]

Question

Short question:

echo '<button type="button" id="add" onClick="addAsset('.$filename.');"> '.$filename.' </button>';

this creates a button with an onClick function addAsset(example.png); But i'd like to have addAsset("example.png") how do i escape the " character?

Thank you!

Answer 1

The end result you'll want to end up with is:

<button type="button" id="add" onClick="addAsset(&quot;example.png&quot;);"> example.png </button>

Otherwise you'll have broken HTML syntax. The alternative is non-conflicting quotes:

<button type="button" id="add" onClick="addAsset('example.png');"> example.png </button>

But you'll still have to escape/encode your input correctly, in case $filename ever contains an undesirable character. The value of the onClick attribute must be valid Javascript, and valid HTML. So:

printf('<button type="button" id="add" onClick="%s"> %s </button>',
       htmlspecialchars(sprintf('addAsset(%s)', json_encode($filename))),
       htmlspecialchars($filename));