filterting/removing an item from object in typescript-CodePudding

How do we filter an object in angular or typescript to remove object that has an empty value for example remove object where annualRent === null . Also what rounding solution can we use to round for example 2.8333333333333335 to 2.83 and remove the other additional decimals like 3333 ....

Thanks.

what I tried and have in mind , something like

array.filter((x): x is MyType => x !== null);

#sample object

[
    {
        "id": 0,
        "type": 0,
        "startDate": "2021-09-27T16:00:00.000Z",
        "endDate": "2021-09-29T16:00:00.000Z",
        "endDateString": "09/30/2021",
        "annualRent": "23232",
        "endDateError": null
    },
    {
        "id": 1,
        "startDate": "2021-09-27T16:00:00.000Z",
        "endDate": "2021-09-29T16:00:00.000Z",
        "endDateString": null,
        "annualRent": null,
        "prevEndDate": "2021-09-29T16:00:00.000Z",
        "useFMV": false
    }
]

CodePudding user response：

You can use the filter method as follows:

arr = [
    {
        "id": 0,
        "type": 0,
        "startDate": "2021-09-27T16:00:00.000Z",
        "endDate": "2021-09-29T16:00:00.000Z",
        "endDateString": "09/30/2021",
        "annualRent": "23232",
        "endDateError": null
    },
    {
        "id": 1,
        "startDate": "2021-09-27T16:00:00.000Z",
        "endDate": "2021-09-29T16:00:00.000Z",
        "endDateString": null,
        "annualRent": null,
        "prevEndDate": "2021-09-29T16:00:00.000Z",
        "useFMV": false
    }
].filter(obj=> obj.annualRent !== null);
console.log(arr);

You can use the method toFixed() to get the number of digits as follows

let num = 2.8333333333333335;
let roundedNum = num.toFixed(2)
console.log(roundedNum);

CodePudding user response：

Try this to filter out objects and at the same time apply rounding to an object property value and debug the results to the console:

let objectList: any[] = 
[
  {
      "id": 0,
      "type": 0,
      "startDate": "2021-09-27T16:00:00.000Z",
      "endDate": "2021-09-29T16:00:00.000Z",
      "endDateString": "09/30/2021",
      "annualRent": "23232",
      "monthlyPay": "2833.3333333333335",
      "endDateError": null
  },
  {
      "id": 1,
      "startDate": "2021-09-27T16:00:00.000Z",
      "endDate": "2021-09-29T16:00:00.000Z",
      "endDateString": null,
      "annualRent": null,
      "monthlyPay": null,
      "prevEndDate": "2021-09-29T16:00:00.000Z",
      "useFMV": false
  },
  {
      "id": 2,
      "startDate": "2021-09-27T16:00:00.000Z",
      "endDate": "2021-09-29T16:00:00.000Z",
      "endDateString": null,
      "annualRent": "12222",
      "monthlyPay": "5000.8889",
      "prevEndDate": "2021-09-29T16:00:00.000Z",
      "useFMV": false
  }      
];

console.log('number of items in list 1 = '   objectList.length);

objectList = objectList.filter(x => x['annualRent'] !== null)
.map((element: any) => 
{
  console.log('monthly pay before = '   element['monthlyPay']);

  let num: number = parseFloat(element['monthlyPay']);
  element['monthlyPay'] = num.toFixed(2);

  console.log('monthly pay after = '   element['monthlyPay']);

  return element;
});

console.log('number of items in original list = '   objectList.length);