Skip to main content

$$if

Conditionally returns a value, if the evaluation of the condition argument is truthy (using the Truthy logic). A fallback value (if condition evaluates to false) is optional

Usage​

{ 
  "$$if": /* Condition */,
  "then": /* any */,
  "else": null /* any */
}
"$$if(<then>,[else]):{input}"
note

Concrete values in the usage example are default values.

note

Alternative form is available using

{
  "$$if": [ /* condition */, /* then */, /* else ? */]
}

If then is used, the primary argument is treated as a condition

Returns​

Any

Arguments​

ArgumentTypeValuesRequired / Default ValueDescription
PrimaryanyYesCondition
thenanyYesValue to return if condition is true
elseanynullValue to return if condition is false

Examples​

Input

Definition

Output

null
{
  "$$if": [
    true,
    "b",
    "c"
  ]
}
"b"
Test
null
{
  "$$if": [
    true,
    "b"
  ]
}
"b"
Test
null
{
  "$$if": [
    false,
    "b"
  ]
}
null
Test
null
{
  "$$if": [
    null,
    "b"
  ]
}
null
Test
[
  "a",
  "b",
  "c"
]
{
  "$$if": [
    "$[0]",
    {
      "$$if": [
        "$[1]",
        "d"
      ]
    }
  ]
}
"d"
Test
[
  false,
  0,
  "true"
]
{
  "$$if": [
    "$[0]",
    "d",
    {
      "$$if": [
        "$[1]",
        "d",
        {
          "$$if": [
            "$[2]",
            "d"
          ]
        }
      ]
    }
  ]
}
"d"
Test
[
  "a",
  "b",
  "c"
]
{
  "$$if": [
    "$[0]",
    "$[1]",
    "$[2]"
  ]
}
"b"
Test
[
  null,
  "b",
  "c"
]
{
  "$$if": [
    "$[0]",
    "$[1]",
    "$[2]"
  ]
}
"c"
Test
[
  "false",
  "b",
  "c"
]
{
  "$$if": [
    "$$boolean:$[0]",
    "$[1]",
    "$[2]"
  ]
}
"c"
Test
[
  true
]
{
  "$$if": "$"
}
null
Test
"hello"
{
  "$$if": "$"
}
null
Test
null
{
  "$$if": true,
  "then": "b",
  "else": "c"
}
"b"
Test
null
{
  "$$if": true,
  "then": "b"
}
"b"
Test
null
{
  "$$if": false,
  "then": "b"
}
null
Test
null
{
  "$$if": "$",
  "then": "b"
}
null
Test
[
  "a",
  "b",
  "c"
]
{
  "$$if": "$[0]",
  "then": {
    "$$if": "$[1]",
    "then": "d"
  }
}
"d"
Test
[
  false,
  0,
  "true"
]
{
  "$$if": "$[0]",
  "then": "d",
  "else": {
    "$$if": "$[1]",
    "then": "d",
    "else": {
      "$$if": "$[2]",
      "then": "d"
    }
  }
}
"d"
Test
[
  "a",
  "b",
  "c"
]
{
  "$$if": "$[0]",
  "then": "$[1]",
  "else": "$[2]"
}
"b"
Test
[
  null,
  "b",
  "c"
]
{
  "$$if": "$[0]",
  "then": "$[1]",
  "else": "$[2]"
}
"c"
Test
[
  "false",
  "b",
  "c"
]
{
  "$$if": "$$boolean:$[0]",
  "then": "$[1]",
  "else": "$[2]"
}
"c"
Test
true
"$$if(a,b):$"
"a"
Test
false
"$$if(a,b):$"
"b"
Test
false
"$$if(a):$"
null
Test