</pre>

<p>
If the map <code>m</code> is <code>nil</code> or the element <code>m[k]</code>
does not exist, <code>delete</code> is a no-op.
</p>


<h3 id="Complex_numbers">Manipulating complex numbers</h3>

<p>
Three functions assemble and disassemble complex numbers.
The built-in function <code>complex</code> constructs a complex
value from a floating-point real and imaginary part, while