$pad

$pad(string?, width, char?) -> string

Compact type signature<s-ns?:s>

If string is omitted, the current context value is used.

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Text

Source: JSONata

Documentation

Returns a copy of the string str with extra padding, if necessary, so that its total number of characters is at least the absolute value of the width parameter. If width is a positive number, then the string is padded to the right; if negative, it is padded to the left. The optional char argument specifies the padding character(s) to use. If not specified, it defaults to the space character.

Examples

Basic usage

• $pad("foo", 5) => "foo "
• $pad("foo", -5) => " foo"
• $pad("foo", -5, "#") => "##foo"
• $formatBase(35, 2) ~> $pad(-8, '0') => "00100011"

Left-pad a line number

Input

This example uses the claims-lines example input. The expression reads the second claim line's lineNumber and pads it for display.

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

$pad($string($[1].lineNumber), -3, "0")

Result

"002"