title: Emit of websocket is repeaded on vuejs and vuex
body: <p>There is a function in vuex file like below.<br>
  When I run start function using 'Button' of Vue component, <br>
  socket.emit sends the data to socker of nodejs. <br>
  And it receives some result through socket.on by websocket of nodejs.</p>
  
  <pre><code>// In vuex.js
  
  const actions = {
     start(event) {    
         socket.emit("voice", {
           msg: event.currentTarget.message
         });
  
         socket.on("voice-reply", result =&gt; {
            console.log(result);
    });
  }
  </code></pre>
  
  <p>But when I run this start function with button of vuejs, <br>
  socket.on("voice-reply") is repeated one  more time. <br>
  For example,</p>
  
  <pre><code>console.log(result)
  </code></pre>
  
  <p>after button click,</p>
  
  <pre><code>console.log(result)
  console.log(result)
  </code></pre>
  
  <p>after button click,</p>
  
  <pre><code>console.log(result)
  console.log(result)
  console.log(result)
  </code></pre>
  
  <p>it runs like this. Could you explain why socket.on is run increasing one more time?<br>
  Thank you so much for reading it.</p>