What does the browser do when the source of iframe is javascript

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When the source of an iframe is:

javascript:\'\';

as in:

</script>
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<p>It tells the browser to display the result of executing the empty string literal. Therefore, it would just display an empty string.</p>

<p>You can test the effect of this by typing in <code>javascript:'http://stackoverflow.com';</code> in the address bar of a normal window/tab. You'll get a white page that says "http://stackoverflow.com" and you won't actually be taken to that URL.</p>

<p>This is the reason that bookmarklets often wrap the code inside <code>void()</code> or an anonymous function that doesn't return anything to stop the browser from trying to display the result of executing the bookmarklet. For example:</p>

<pre><code>javascript:void(window.open("dom_spy.html"))
</code></pre>

<p>Or:</p>

<pre><code>javascript:(function () { window.open("dom_spy.html"); })()
</code></pre>

<p>If you directly use code that returns something (a new window instance in this case), the browser will end up displaying that:</p>

<pre><code>javascript:window.open("dom_spy.html");
</code></pre>

<p>In Firefox the above will display:</p>

<pre>[object Window]</pre>
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                <span>2021-01-05 06:00</span>
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<p>To the best of my knowledge the <code>src</code> attribute maps to the <code>iframe</code> elements <code>location.href</code>.  So setting <code>src</code> to <code>javascript:'';</code> is a bit nonsensical and the browser will do one of two things:</p>

<ul>
<li>Ignore it because it is not a URI and does not resolve to any displayable resource</li>
<li>Execute the javascript which produced nothing</li>
</ul>

<p>Either way you accomplish very little.  Is this code you inherited or are you trying to do something tricky with the <code>iframe</code>?</p>
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