title: change object value v-for inside v-for in vue.js
body: <p>I am quite new in vue.
  I have 2 array data like this :</p>
  <pre><code>listAccount : [
      {
          id_acc : a,
          amount : 1000
      },
      {
          id_acc : b,
          amount : 2000
      },
      {
          id_acc : c,
          amount : 1000
      }
  ]
  
  listTransaction : [
      {
          id_acc : a,
          type : inc,
          amount : 100
      },
      {
          id_acc : b,
          type : inc,
          amount : 100
      },
      {
          id_acc : a,
          type : dec,
          amount : 100
      },
      {
          id_acc : a,
          type : dec,
          amount : 100
      }
  ]
  </code></pre>
  <p>and this is my component code</p>
  <pre><code>&lt;div v-for=&quot;(list,index) in listAccount&quot; :key=&quot;index&quot;&gt;
      &lt;div&gt; {{list.id_acc}} -- {{list.amount}} &lt;/div&gt;
      &lt;div&gt; transaction :&lt;/div&gt;
      &lt;div v-for=&quot;(each, index) in listTransaction&quot; :key=&quot;index&quot;&gt;
          &lt;div v-if=&quot;each.id_acc == list.id_acc&quot;&gt;
              &lt;div&gt; {{list.type == inc ? list.amount + each.amount : list.amount - each.amount}} &lt;/div&gt;
          &lt;/div&gt;
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  <p>i got result like this</p>
  <pre><code>my result:
  a -- 1000
  transaction:
      1100
      900
      900
  
  b -- 2000
  transaction:
      2100
  
  c -- 1000
  transaction:
  </code></pre>
  <p>but i want my result if the transaction type &quot;inc&quot;, the transaction amount increase the amount of my account and if transaction type &quot;dec&quot;, the transaction amount decrease the amount of my account if the transaction have same id_acc. my expected result like this:</p>
  <pre><code>expected result :
  
  a -- 1000
  transaction:
      1100
      1000
      900
  
  b -- 2000
  transaction:
      2100
  
  c -- 1000
  transaction:
  </code></pre>
  <p>i don't know how to change parent element value. can someone help me?</p>