How to merge two object and returned combined object using javascript

For Merging two different object you can do this

/**
 * Merge Two objects and return combined object
 */
merge = (target, source) => {
  // Iterate through `source` properties and if an `Object` set property to merge of `target` and `source` properties
  for (const key of Object.keys(source)) {
    if (source[key] instanceof Object) {
      if (target[key]) {
        Object.assign(source[key], this.merge(target[key], source[key]));
      }
    }
  }
  // Join `target` and modified `source`
  return Object.assign({}, target || {}, source);
};