title: How to map key/value pairs of a "map" in JavaScript?
body: <p>How to map key/value pairs of a "map" in JavaScript:</p>
  
  <pre><code>var map = {"a": 1, "b": 2, "c": 3};
  
  alert(JSON.stringify(map));
  </code></pre>
  
  <p>I need to get an mapper containing key/value pair on each iteration:</p>
  
  <pre><code>// ["a_1", "b_2", "c_3"]
  map.map((key, value) =&gt; key + "_" + value);
  </code></pre>