=proto
void duk_to_undefined(duk_context *ctx, duk_idx_t index);

=stack
[ ... val! ... ] -> [ ... undefined! ... ]

=summary
<p>Replace the value at <code>index</code> with <code>undefined</code>, regardless
of the previous value.  Throws an error if index is invalid.</p>

<div class="note">
Equivalent to <code>duk_push_undefined()</code> followed by <code>duk_replace()</code>
to target index.
</div>

=example
duk_to_undefined(ctx, -3);

=tags
stack

=introduced
1.0.0