对象数组（扁平）转为树形数组

梦里梦外; 2022-10-24 13:13 179阅读 0赞

let arr = [
        {  'country': '国内', 'reputation': '985', 'university': '北京大学', 'university_id': 'beijig' },
        {  'country': '国内', 'reputation': '211', 'university': '清华大学', 'university_id': 'qinghua' },
        {  'country': '国内', 'reputation': '985', 'university': '浙江大学', 'university_id': 'zhejiang' },
        {  'country': '国内', 'reputation': '211', 'university': '武汉大学', 'university_id': 'wuhan' },
        {  'country': '国内', 'reputation': '其它', 'university': '邯郸大学', 'university_id': 'handan' },
        {  'country': '国内', 'reputation': '其它', 'university': '沧州大学', 'university_id': 'cangzhou' },
        {  'country': '国外', 'reputation': '其它', 'university': '哈弗大学', 'university_id': 'hafu' },
        {  'country': '国外', 'reputation': '其它', 'university': '剑桥大学', 'university_id': 'jianqiao' },
        {  'country': '国外', 'reputation': '其它', 'university': '牛津大学', 'university_id': 'niujin' }
      ]

转为

let arr1 = [
        { 
          country: '国内',
          children: [
            { 
              reputation: '985', 
              children: [
                { 
                  university: '北京大学',
                  university_id: 'beijing'
                },
                { 
                  university: '浙江大学',
                  university_id: 'zhejiang'
                }
              ]
            }, 
            { 
              reputation: '211', 
              children: [
                { 
                  university: '清华大学',
                  university_id: 'qinghua'
                },
                { 
                  university: '武汉大学',
                  university_id: 'wuhan'
                }
              ]
            }, 
            { 
              reputation: '其他', 
              children: [
                { 
                  university: '邯郸大学',
                  university_id: 'handan'
                },
                { 
                  university: '沧州大学',
                  university_id: 'cangzou'
                }
              ]
            }, 
          ]
        }, 
        { 
          country: '国外',
          children: [
            { 
              reputation: '其他', 
              children: [
                { 
                  university: '哈弗大学',
                  university_id: 'hafu'
                }, 
                { 
                  university: '剑桥大学',
                  university_id: 'jianqiao'
                }, 
                { 
                  university: '牛津大学',
                  university_id: 'niujin'
                }, 
              ]
            }
          ]
        }
      ]

递归分组

// TEST （原问答来自segmentfault 普拉斯强）
    function groupBy(arr, ...groupKeys) { 
        const [key, ...restGroupKeys] = groupKeys;
        const groupObj = Object.entries(arr.reduce((result, item) => { 
            const {  [key]: grouKey, ...restProps } = item;
            const list = result[grouKey] = result[grouKey] || [];
            list.push(restProps);
            return result
        }, []));
        
        return groupObj.map(([groupKey, children]) => { 
            return {  
                [key]: groupKey, 
                children: restGroupKeys.length ? groupBy(children, ...restGroupKeys) : children
            }
        })
    }
    
    groupBy(arr, 'country', 'reputation');