title: React - How do you call a function from inside another function
body: <p>Suppose I had this layout below:</p>
  
  <pre><code>class Navigation extends React.Component {
   primaryFun() { console.log('funn') }
  
   secondaryFun() {
    this.primaryFun();
   }
  }
  </code></pre>
  
  <p>I'd of expected this to then call primary but instead I get an undefined, Ok. </p>
  
  <p>So I thought I'd add a constructor to bind the function to this:</p>
  
  <pre><code>constructor(props) {
   super(props)
   this.primaryFun = this.primaryFun.bind(this);
  }
  </code></pre>
  
  <p>but primary fun is still undefined. </p>
  
  <p>In my real project I'm calling these on a mouseOut event.</p>
  
  <p>Feels like the above should work and tbh the documentation for React is all over the shot so couldn't find much here. </p>