<!-- jQuery -->
<h2>jQuery</h2>
<table id="t1">
  <tr>
    <th>Item</th>
    <th>Quantity</th>
  </tr>
  <tr id="r1">
    <td><input name="item[]" type="text"/></td>
    <td><input name="quantity[]" type="number"/></td>
    <td><button class="deleteRow">X</button></td>
  </tr>
</table>
<button id="addRow">Add Row</button>

// jQuery
$(document).on('click', '#addRow', function(){
    var row = parseInt($('#t1 tr:last-child').attr('id')) + 1;
    alert(row);
        $('#t1').append('<tr id="r'+row+'"><td><input name="item[]" type="text"/></td><td><input name="quantity[]" type="number"/></td><td><button class="deleteRow">X</button></td></tr>');
});

$(document).on('click', '.deleteRow', function(){
        var row = parseInt($(this).closest('tr').attr('id'));
    $('#r'+row).remove();
});

<div id="app">

    <ul>
      <li v-for="(input, index) in inputs">
        <input type="text" v-model="input.one"> - {{ input.one }}
        <input type="text" v-model="input.two"> - {{ input.two }}
        <button @click="deleteRow(index)">Delete</button>
      </li>
    </ul>

    <button @click="addRow">Add row</button>

  </div>

const app = new Vue({

  el: '#app',

  data: {
    inputs: []
  },

  methods: {
    addRow() {
      this.inputs.push({
        one: '',
        two: ''
      })
    },
    deleteRow(index) {
      this.inputs.splice(index,1)
    }
  }

})