Javascript数组过滤器函数删除键值

Question

I have an array of Javascript objects indexed by key values listed below, each key representing a Javascript object (this is just a console.log() of the key values in the array):

[ '532',
  '789',
  '1232',
  '2346',
  '3404',
  '4991',
  '5323',
  '5378',
  '8923',
  '9876',
  '23434',
  '23549',
  '24454',
  '34234',
  '45667',
  '48983',
  '67834',
  '72342',
  '82434',
  '89829',
  '98732',
  '123404',
  '143454',
  '234345',
  '345294',
  '532234',
  '532342',
  '532345',
  '532349',
  '989898' ]

When I console.log() out this Javascript array it is "filled-in" with "NULL" values. For example the first key is 532, so when printing this array out first there are 531 "NULL" values printed and the then Javascript object with key 532 and so on for each key.

So my solution is to remove the null values by running this function below on the array:

teamData = teamData.filter(function (el) {
   return el != null && el != "";
});

My Issue: . Once I run that filter function the array key values are reset to:

[ '0',
  '1',
  '2',
  '3',
  '4',
  '5',
  '6',
  '7',
  '8',
  '9',
  '10',
  '11',
  '12',
  '13',
  '14',
  '15',
  '16',
  '17',
  '18',
  '19',
  '20',
  '21',
  '22',
  '23',
  '24',
  '25',
  '26',
  '27',
  '28',
  '29' ]

Question: Is there a way to filter out the null values between the array keys while still keeping the key values in the first array? Is there another way to structure this data so there won't be null values?

Answer 1

Problem is that you're trying to use an array index position as key. This won't work because arrays always have consecutive indexes starting from 0. So if you gonna have an element at index 532 then there necessarily will be 532 elements before it (0 to 531). If you remove those elements with filter the indexes will shift to the correct position, in your case from 0 o 29. In Javascript there is a native object for your use case, it is called Map, here you can read everything about it.