js多层对象数组 合并_JS对象数组合并去重？

可以使用JavaScript的reduce()和concat()方法来合并多层对象数组。以下是一个示例代码，它将合并具有相同ID属性的对象，并将它们的数量相加：

const arr1 = [{id: 1, name: 'A', count: 2}, {id: 2, name: 'B', count: 3}];
const arr2 = [{id: 1, name: 'A', count: 4}, {id: 3, name: 'C', count: 1}];

const mergedArr = [...arr1, ...arr2].reduce((acc, curr) => {
  const index = acc.findIndex(item => item.id === curr.id);
  if (index === -1) {
    return [...acc, curr];
  } else {
    acc[index].count += curr.count;
    return acc;
  }
}, []);

console.log(mergedArr);
// Output: [{id: 1, name: 'A', count: 6}, {id: 2, name: 'B', count: 3}, {id: 3, name: 'C', count: 1}]

如果要合并多层对象数组，可以使用递归来处理每个子数组。以下是一个示例代码：

const arr1 = [{id: 1, children: [{id: 2, name: 'A', count: 2}]}, {id: 3, name: 'B', count: 3}];
const arr2 = [{id: 1, children: [{id: 2, name: 'A', count: 4}]}, {id: 4, name: 'C', count: 1}];

function mergeArrays(arr1, arr2) {
  const mergedArr = [...arr1, ...arr2].reduce((acc, curr) => {
    const index = acc.findIndex(item => item.id === curr.id);
    if (index === -1) {
      return [...acc, curr];
    } else if (curr.children) {
      acc[index].children = mergeArrays(acc[index].children, curr.children);
      return acc;
    } else {
      acc[index].count += curr.count;
      return acc;
    }
  }, []);
  return mergedArr;
}

const result = mergeArrays(arr1, arr2);
console.log(result);
// Output: [{id: 1, children: [{id: 2, name: 'A', count: 6}]}, {id: 3, name: 'B', count: 3}, {id: 4, name: 'C', count: 1}]

这个示例代码中，mergeArrays()函数使用递归来处理每个子数组，直到没有子数组为止。在每个子数组中，它再次使用reduce()方法来合并具有相同ID属性的对象。如果当前对象具有子数组，则递归处理该子数组。否则，它将增加当前对象的数量。最终，该函数将返回合并后的数组。