title: Arrow functions: What is this block explaining?
body: <pre><code>function readJson(sample) {
      d3.json("samples.json").then((data) =&gt; {
          var extract = data.metadata
          var emptyArray = extract.filter(object =&gt; object.id == sample);
          var finalArray = emptyArray[0];
          var Visual = d3.select("#sample-metadata");
  
          Object.entries(finalArray).forEach(([key, value]) =&gt; {
              Visual.append("h6").text(`${key} : ${value}`);
          });
      });
  }
  </code></pre>
  
  <p>My friend handed over this code for me but I'm having a hard time understanding the arrow functions. Can anyone explain what this function is performing? The ID and JSON files are saved as separate files.</p>