title: React Arrow Function Component - setState is not defined
body: <p>I am trying to setState in an arrow function component but getting an error "setState is not defined".</p>
  
  <p>I tried setting state in handleChange using <code>setState({ selectedSlot })</code> and <code>this.setState({ selectedSlot })</code> but nothing worked.</p>
  
  <pre><code> const AddAssetActivity = props =&gt; {
   let { variations, slots, priceStructure } = props;
  
   let state = {
     selectedSlot: { "0": "00", "1": "11" },
     cal: 1
   };
  
   let handleChange = (event, value) =&gt; {
     let selectedSlot = state.selectedSlot;
     selectedSlot[value.variation] = value.slot;
     setState({ selectedSlot });
   };
  
   return (
     &lt;div&gt;
  
     &lt;/div&gt;
   );
  };
  </code></pre>