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$filter

$filter(array, function) -> array
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Arrays And SequencesFunctions That Use Other Functions

Source: JSONata

Documentation​

Returns the input items whose callback result is truthy under JSONata boolean rules.

The callback receives the current value, index, and source array. $filter() keeps the original matching items rather than the callback result, and undefined input returns undefined. Unlike $first(), $pMap(), and $pLimit(), this implementation expects an array or sequence input rather than wrapping a scalar as a one-item sequence.

Examples​

Filter for higher-cost lines​

Input

This example uses the claims-lines example input. The expression filters the claim lines for higher-cost entries.

Example input

JSON
[
  {
    "claimId": "clm-2001",
    "lineNumber": 1,
    "serviceCode": "PROC-010",
    "serviceDisplay": "office visit",
    "units": 1,
    "unitPrice": 125,
    "allowedAmount": 110,
    "modifiers": [
      "MOD-A"
    ]
  },
  {
    "claimId": "clm-2001",
    "lineNumber": 2,
    "serviceCode": "PROC-020",
    "serviceDisplay": "imaging study",
    "units": "1",
    "unitPrice": 350,
    "allowedAmount": 300,
    "modifiers": [
      "MOD-B",
      "MOD-C"
    ]
  },
  {
    "claimId": "clm-2001",
    "lineNumber": 3,
    "serviceCode": "PROC-030",
    "serviceDisplay": "lab panel",
    "units": 2,
    "unitPrice": 40,
    "allowedAmount": 70,
    "modifiers": []
  },
  {
    "claimId": "clm-2002",
    "lineNumber": 1,
    "serviceCode": "PROC-010",
    "serviceDisplay": "office visit",
    "units": 1,
    "unitPrice": 125,
    "allowedAmount": 115,
    "modifiers": [
      "MOD-A"
    ]
  },
  {
    "claimId": "clm-2002",
    "lineNumber": 2,
    "serviceCode": "PROC-040",
    "serviceDisplay": "counseling",
    "units": 3,
    "unitPrice": 60,
    "allowedAmount": 150,
    "modifiers": [
      "MOD-D"
    ]
  }
]

Expression

$filter($, function($l) { $l.allowedAmount >= 150 }).{ "claimId": claimId, "lineNumber": lineNumber, "allowedAmount": allowedAmount }

Result

[
  { "claimId": "clm-2001", "lineNumber": 2, "allowedAmount": 300 },
  { "claimId": "clm-2002", "lineNumber": 2, "allowedAmount": 150 }
]