JS Code for Drag & Drop Demo LWC | Variables & connectedCallback

dragAndDrop.js

import { LightningElement, track } from 'lwc';

const COLUMNS = [
  {
    label: 'Id',
    fieldName: 'id',
    hideDefaultActions: true
  },
  {
    label: 'Label',
    fieldName: 'label',
    hideDefaultActions: true
  }
];

export default class DragAndDrop extends LightningElement {
  elements = [];
  columns = COLUMNS;
  @track data = [];

  connectedCallback() {
    for (let i = 1; i <= 12; i++) {
      this.elements.push({ id: i, label: `Element ${i}` });
    }
  }
}