Question

我有一个像这样的对象数组

events = [ {
    'summary': 'sample test events1',
    'location': 'coimbatore',
    'start': {
        'date': '2018-08-28',
        'timeZone': 'America/Los_Angeles'
    },
    'end': {
        'date': '2018-08-28',
        'timeZone': 'America/Los_Angeles'
    }
    },
    {
      'summary': 'sample test events2',
      'location': 'coimbatore',
      'start': {
          'date': '2018-08-29',
          'timeZone': 'America/Los_Angeles'
      },
      'end': {
          'date': '2018-08-29',
          'timeZone': 'America/Los_Angeles'
      }
    },
    {
    'summary': 'sample test events4',
    'location': 'coimbatore',
    'start': {
        'date': '2018-08-27',
        'timeZone': 'America/Los_Angeles'
    },
    'end': {
        'date': '2018-08-27',
        'timeZone': 'America/Los_Angeles'
    }
    },
    {
      'summary': 'sample test events5',
      'location': 'coimbatore',
      'start': {
          'date': '2018-08-26',
          'timeZone': 'America/Los_Angeles'
      },
      'end': {
          'date': '2018-08-26',
          'timeZone': 'America/Los_Angeles'
      }
      }];

我有另一个要过滤的对象数组

toFilterEvents = [
{startDate: "2018-08-28", summary: "sample test events1"},
{startDate: "2018-08-29", summary: "sample test events2"},
]

我希望结果像，

events = [ 

    {
    'summary': 'sample test events4',
    'location': 'coimbatore',
    'start': {
        'date': '2018-08-27',
        'timeZone': 'America/Los_Angeles'
    },
    'end': {
        'date': '2018-08-27',
        'timeZone': 'America/Los_Angeles'
    }
    },
    {
      'summary': 'sample test events5',
      'location': 'coimbatore',
      'start': {
          'date': '2018-08-26',
          'timeZone': 'America/Los_Angeles'
      },
      'end': {
          'date': '2018-08-26',
          'timeZone': 'America/Los_Angeles'
      }
      }];

我尝试了什么，

filterExistingEvents(toFilterEvents);

filterExistingEvents(filtered_events) {
    const hello = this.events.filter((r, i) => {
      return filtered_events.some(f => r.summary !== f.summary)
    });
    console.log('events after filter', hello, this.events);  
}

正如你所看到我正在使用过滤器和一些来获得所需的输出，如上所示，但它不起作用。我发现类似这样的问题，但这是在没有toFilterEvents

的情况下返回事件

Answer 1

如果数组元素中至少有一个与条件匹配，则

Array.prototype.some返回true 如果所有数组元素都匹配条件<{p>，则Array.prototype.every返回true

filterExistingEvents(filtered_events) {
    const hello = this.events.filter((r, i) => {
      return filtered_events.every(f => r.summary !== f.summary)
    });
    console.log('events after filter', hello, this.events);  
}

Answer 2

看起来您希望对多个字段进行过滤，因此最好使用高阶函数创建过滤函数，可以找到详细示例here。

我认为你实际上是在寻找一些而不是每一次的反转。

＆＃13;

const events = [{
  'summary': 'sample test events1',
  'location': 'coimbatore',
  'start': {
    'date': '2018-08-28',
    'timeZone': 'America/Los_Angeles'
  },
  'end': {
    'date': '2018-08-28',
    'timeZone': 'America/Los_Angeles'
  }
},
{
  'summary': 'sample test events2',
  'location': 'coimbatore',
  'start': {
    'date': '2018-08-29',
    'timeZone': 'America/Los_Angeles'
  },
  'end': {
    'date': '2018-08-29',
    'timeZone': 'America/Los_Angeles'
  }
},
{
  'summary': 'sample test events4',
  'location': 'coimbatore',
  'start': {
    'date': '2018-08-27',
    'timeZone': 'America/Los_Angeles'
  },
  'end': {
    'date': '2018-08-27',
    'timeZone': 'America/Los_Angeles'
  }
},
{
  'summary': 'sample test events5',
  'location': 'coimbatore',
  'start': {
    'date': '2018-08-26',
    'timeZone': 'America/Los_Angeles'
  },
  'end': {
    'date': '2018-08-26',
    'timeZone': 'America/Los_Angeles'
  }
}];

const filterFn = getter => comparer => o =>
  comparer(getter(o))
;
const isNotIn = hayStack => needle =>
  !hayStack.some(x=>x===needle)
;
const summary = o => o.summary;
const startDate = o => o.start.date;
const toFilterEvents = [
  { startDate: "2018-08-28", summary: "sample test events1" },
  { startDate: "2018-08-29", summary: "sample test events2" },
];
//filter out any events that have summary or startDate in toFilterEvents
console.log(
  events.filter(
    filterFn(summary)(isNotIn(toFilterEvents.map(x=>x.summary)))
  ).filter(
    filterFn(startDate)(isNotIn(toFilterEvents.map(x=>x.startDate)))
  ).map(x=>x.summary)
);
//filter out any events that have summary and startDate in toFilterEvents
console.log(
  events.filter(
    (
      (summaries,startDates)=>item=>
        filterFn(summary)(isNotIn(summaries))(item) ||
        filterFn(startDate)(isNotIn(startDates))(item)
    )(toFilterEvents.map(x=>x.summary),toFilterEvents.map(x=>x.startDate))
  ).map(x=>x.summary)
);

＆＃13;

使用带有filter和some的另一个object对象过滤一个对象数组

2 个答案: