javascript - Iframe without src but still has content?

Question

While debugging jquery code on their site ( via chrome developer toolbar)

I noticed that their examples are given under Iframe :

Here - for example there is a sample which is under an Iframe but after investigating , I see that the Iframe doesn't have SRC

The picture shows it all

Question :

Is it possible to set content to an Iframe without setting its SRC ?

p.s. this menu also shows me an empty content

Answer 1

Yes, it is possible to load an empty <iframe> (with no src specified) and later apply content to it using script.

See: http://api.jquery.com/jquery-wp-content/themes/jquery/js/main.js (line 54 and below).

Or simply try:

<iframe></iframe>

<script>
document.querySelector('iframe')
        .contentDocument.write("<h1>Injected from parent frame</h1>")
</script>