title: How to create an array of custom types typescript
body: <p>I have an interface with the following:</p>
  
  <pre><code>interface orderItem {
    symbol: string,
    side: string,
    price: number
    quantity: number
  }
  </code></pre>
  
  <p>I want to create an array "orders" consisting of "orderItems" in my constructor. </p>
  
  <p>However, orders : [orderItem] doesn't seem to be doing the trick. Does anyone know how I can proceed?</p>
  
  <p>Here is what I am trying to do in my constructor:</p>
  
  <pre><code>   this.state = {
        orders: orderItem []
  
    } 
  </code></pre>