title: How to calculate two input values and put the result in another input field in Vue,js?
body: <p>Here are my input fields:</p>
  <pre><code>&lt;input v-model=&quot;form.sale_quantity&quot; @change=&quot;computed&quot; type=&quot;number&quot; class=&quot;form-control&quot; name=&quot;sale_quantity&quot; id=&quot;sale_quantity&quot; placeholder=&quot;Quantity&quot;&gt;
  
  &lt;input v-model=&quot;form.sale_rate&quot; @change=&quot;computed&quot; type=&quot;number&quot; step=&quot;any&quot; class=&quot;form-control&quot; name=&quot;sale_rate&quot; id=&quot;sale_rate&quot; placeholder=&quot;Rate&quot;&gt;
  
  &lt;input v-model=&quot;form.sale_total&quot; type=&quot;number&quot; step=&quot;any&quot; class=&quot;form-control&quot; name=&quot;sale_total&quot; id=&quot;sale_total&quot; placeholder=&quot;Total Price&quot;&gt;
  </code></pre>
  <p>I am using on change method to check whether the two input fields have some values and then calculate them.</p>
  <pre><code>data() {
      return {                
          form: new Form({
              sale_quantity: '',
              sale_rate: '',
              sale_total: '',
          })
      }
  },
  methods: {              
      computed() {
          //computation here
      }
  }
  </code></pre>
  <p>So what should be my computed() method to check the input fields and calculate them to fill in the third input field?</p>