class="anchor"></a><code><span class="keyword">method</span> length : <span>int <a href="../index.html#type-prop">prop</a></span></code></dt><dt class="spec method" id="method-map"><a href="#method-map" class="anchor"></a><code><span class="keyword">method</span> map : <span><span>(<span class="type-var">'a</span> <span>&#45;&gt;</span> int <span>&#45;&gt;</span> <span><span><span class="type-var">'a</span> <a href="index.html">js_array</a></span> <a href="../index.html#type-t">t</a></span> <span>&#45;&gt;<