title: Vue axios call is claiming argument is null when should be an array
body: <p>In my vue component I have a data array</p>
  <pre><code>data: {
    categories: [{id:1, title: &quot;category 1&quot;},{id:2, title: &quot;category 2&quot;}]
  }
  </code></pre>
  <p>and I'm trying to load this in as a data argument in an axios call</p>
  <pre><code>axios({
    method: 'get',
    url: //testURL,
    data: {
      categoryCall: this.categories
    }
  }).then(function (response){
    console.log(response);
  }).catch(function (error){
    console.log(error.response);
  });
  </code></pre>
  <p>but I'm getting a 400 bad request code where it tells me that argument 1 should be an array and null is given.</p>
  <p>Am I not properly passing in the already established array in the axios call? Where am I going wrong?</p>
  <p><div class="snippet" data-lang="js" data-hide="false" data-console="true" data-babel="false">
  <div class="snippet-code">
  <pre class="snippet-code-js lang-js prettyprint-override"><code>var vm = 
  new Vue({
    el: "#app",
    data: {
      categories: [
      {id:1, title: "category 1"},
      {id:2, title: "category 2"}
      ]
    },
    methods: {
      submit_axios(){
      
          axios({
              method: 'get',
              url: //test,
              data: {
                categories: this.categories
              }
  
          }).then(function (response) {
              console.log(response);
  
          }).catch(function (error) {
              console.log(error.response);
          });
      }
    }
    
  })</code></pre>
  <pre class="snippet-code-html lang-html prettyprint-override"><code>&lt;script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"&gt;&lt;/script&gt;
  &lt;div id="app"&gt;
     &lt;button  @click="submit_axios()"&gt;Search&lt;/button&gt;
  &lt;/div&gt;</code></pre>
  </div>
  </div>
  </p>