=proto
double duk_require_number(duk_context *ctx, int index);

=stack
[ ... val! ... ]

=summary
<p>Like <code><a href="#duk_get_number">duk_get_number()</a></code>,
but throws an error if the value at <code>index</code> is not a number
or if the index is invalid.</p>

=example
printf("value: %lf\n", duk_require_number(ctx, -3));

=tags
stack