title: Why return statement is explicitly required in function?
body: <p>When the compiler is aware of what it returns (fullName in the example), why it expects explicit return statement?</p>
  <pre><code>func fullName(firstName string, lastName string) (fullName string) {
      fullName = firstName + &quot; &quot; + lastName
      return // Why explicit return?
  }
  </code></pre>