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`IsBoolean`

This reference topic applies to FQL v4. Go to this page for the latest FQL v10 reference topics.

IsBoolean( value )

is_boolean( value )

IsBoolean( value )

IsBoolean( value )

IsBoolean( value )

Description

The IsBoolean function returns true only if value is a Boolean, otherwise it returns false.

Parameters

Parameter Type Definition and Requirements

Parameter	Type	Definition and Requirements
`value`	Any	Any value, which is to be tested to determine whether it is a Boolean or not.

value

Any

Any value, which is to be tested to determine whether it is a Boolean or not.

Returns

Returns a Boolean, indicating whether value was a Boolean or not.

Examples

The following query uses Map to iterate over an array of all of the types of values that can be tested by a type-check function, passing each item into a Lambda function that returns an object, which contains the value and the result of calling IsBoolean with that value:

client.query(
  q.Map(
    [
      ['array'],
      true,
      false,
      new Uint8Array([1, 2, 3, 4]),
      [0x1, 0x2, 0x3, 0x4],
      q.Collection('Letters'),
      q.Ref('credentials/self'),
      q.Database('child_db'),
      q.Date('2019-11-12'),
      q.Ref(q.Collection('Letters'), 123),
      10.1,
      q.Function('double'),
      q.Index('letters'),
      10,
      q.Ref(q.Keys(), '248967241620521472'),
      q.Query(q.Lambda('x', q.Var('x'))),
      null,
      { x: 10 },
      q.Role('employees'),
      q.Match(q.Index('letters')),
      'ten',
      '10',
      q.Time('2020-07-06T12:34:56.789Z'),
      q.Ref(q.Tokens(), '249062079147803136'),
    ],
    q.Lambda('x', {
      value: q.Var('x'),
      IsBoolean: q.IsBoolean(q.Var('x')),
    })
  )
)
.then((ret) => console.log(ret))
.catch((err) => console.error(
  'Error: [%s] %s: %s',
  err.name,
  err.message,
  err.errors()[0].description,
))

[
  { value: [ 'array' ], IsBoolean: false },
  { value: true, IsBoolean: true },
  { value: false, IsBoolean: true },
  { value: Bytes("AQIDBA=="), IsBoolean: false },
  { value: [ 1, 2, 3, 4 ], IsBoolean: false },
  { value: Collection("Letters"), IsBoolean: false },
  { value: Ref(Credentials(), "268417928845591040"), IsBoolean: false },
  { value: Database("child_db"), IsBoolean: false },
  { value: Date("2019-11-12"), IsBoolean: false },
  { value: Ref(Collection("Letters"), "123"), IsBoolean: false },
  { value: 10.1, IsBoolean: false },
  { value: Function("double"), IsBoolean: false },
  { value: Index("letters"), IsBoolean: false },
  { value: 10, IsBoolean: false },
  { value: Ref(Keys(), "248967241620521472"), IsBoolean: false },
  { value: Query(Lambda("x", Var("x"))), IsBoolean: false },
  { value: null, IsBoolean: false },
  { value: { x: 10 }, IsBoolean: false },
  { value: Role("employees"), IsBoolean: false },
  { value: Match(Index("letters")), IsBoolean: false },
  { value: 'ten', IsBoolean: false },
  { value: '10', IsBoolean: false },
  { value: Time("2020-06-15T17:28:56.030Z"), IsBoolean: false },
  { value: Ref(Tokens(), "249062079147803136"), IsBoolean: false }
]

result = client.query(
  q.map_(
    q.lambda_("x", {
      "value": q.var("x"),
      "IsBoolean": q.is_boolean(q.var("x")),
    }),
    [
      ["array"],
      True,
      False,
      bytearray([1, 2, 3, 4]),
      [0x1, 0x2, 0x3, 0x4],
      q.collection("Letters"),
      q.ref("credentials/self"),
      q.database("child_db"),
      q.date("2019-11-12"),
      q.ref(q.collection("Letters"), 123),
      10.1,
      q.function("double"),
      q.index("letters"),
      10,
      q.ref(q.keys(), "1"),
      q.query(q.lambda_("x", q.var("x"))),
      None,
      {"x": 10},
      q.role("employees"),
      q.match(q.index("letters")),
      "ten",
      "10",
      q.time("2020-07-06T12:34:56.789Z"),
      q.ref(q.tokens(), "1"),
    ],
  )
)
print(result)

[{'value': ['array'], 'IsBoolean': False}, {'value': True, 'IsBoolean': True}, {'value': False, 'IsBoolean': True}, {'value': bytearray(b'\x01\x02\x03\x04'), 'IsBoolean': False}, {'value': [1, 2, 3, 4], 'IsBoolean': False}, {'value': Ref(id=Letters, collection=Ref(id=collections)), 'IsBoolean': False}, {'value': Ref(id=282032258185953792, collection=Ref(id=credentials)), 'IsBoolean': False}, {'value': Ref(id=child_db, collection=Ref(id=databases)), 'IsBoolean': False}, {'value': datetime.date(2019, 11, 12), 'IsBoolean': False}, {'value': Ref(id=123, collection=Ref(id=Letters, collection=Ref(id=collections))), 'IsBoolean': False}, {'value': 10.1, 'IsBoolean': False}, {'value': Ref(id=double, collection=Ref(id=functions)), 'IsBoolean': False}, {'value': Ref(id=letters, collection=Ref(id=indexes)), 'IsBoolean': False}, {'value': 10, 'IsBoolean': False}, {'value': Ref(id=1, collection=Ref(id=keys)), 'IsBoolean': False}, {'value': Query({'api_version': '4', 'lambda': 'x', 'expr': {'var': 'x'}}), 'IsBoolean': False}, {'value': None, 'IsBoolean': False}, {'value': {'x': 10}, 'IsBoolean': False}, {'value': Ref(id=employees, collection=Ref(id=roles)), 'IsBoolean': False}, {'value': SetRef({'match': Ref(id=letters, collection=Ref(id=indexes))}), 'IsBoolean': False}, {'value': 'ten', 'IsBoolean': False}, {'value': '10', 'IsBoolean': False}, {'value': FaunaTime('2020-07-06T12:34:56.789Z'), 'IsBoolean': False}, {'value': Ref(id=1, collection=Ref(id=tokens)), 'IsBoolean': False}]

result, err := client.Query(
	f.Map(
		f.Arr{
			f.Arr{"array"},
			true,
			false,
			f.BytesV{0x01, 0x02, 0x03, 0x04},
			f.Arr{0x1, 0x2, 0x3, 0x4},
			f.Collection("Letters"),
			f.Ref("credentials/self"),
			f.Database("child_db"),
			f.Date("2019-11-12"),
			f.Ref(f.Collection("Letters"), 123),
			10.1,
			f.Function("double"),
			f.Index("letters"),
			10,
			f.Ref(f.Keys(), "1"),
			f.Query(f.Lambda("x", f.Var("x"))),
			nil,
			f.Null(),
			f.Obj{"x": 10},
			f.Role("employees"),
			f.Match(f.Index("letters")),
			"ten",
			"10",
			f.Time("2020-07-06T12:34:56.789Z"),
			f.Ref(f.Tokens(), "1"),
		},
		f.Lambda("x", f.Obj{
			"value": f.Var("x"),
			"IsBoolean": f.IsBoolean(f.Var("x")),
		})))

if err != nil {
	fmt.Fprintln(os.Stderr, err)
} else {
	fmt.Println(result)
}

[map[IsBoolean:false value:[array]] map[IsBoolean:true value:true] map[IsBoolean:true value:false] map[IsBoolean:false value:[1 2 3 4]] map[IsBoolean:false value:[1 2 3 4]] map[IsBoolean:false value:{Letters 0xc0001901e0 0xc0001901e0 <nil>}] map[IsBoolean:false value:{280481857410171392 0xc000190300 0xc000190300 <nil>}] map[IsBoolean:false value:{child_db 0xc000190420 0xc000190420 <nil>}] map[IsBoolean:false value:{0 63709113600 <nil>}] map[IsBoolean:false value:{123 0xc0001906f0 0xc0001906f0 <nil>}] map[IsBoolean:false value:10.1] map[IsBoolean:false value:{double 0xc000190840 0xc000190840 <nil>}] map[IsBoolean:false value:{letters 0xc000190960 0xc000190960 <nil>}] map[IsBoolean:false value:10] map[IsBoolean:false value:{1 0xc000190ab0 0xc000190ab0 <nil>}] map[IsBoolean:false value:{[123 34 97 112 105 95 118 101 114 115 105 111 110 34 58 34 51 34 44 34 108 97 109 98 100 97 34 58 34 120 34 44 34 101 120 112 114 34 58 123 34 118 97 114 34 58 34 120 34 125 125]}] map[IsBoolean:false value:{}] map[IsBoolean:false value:{}] map[IsBoolean:false value:map[x:10]] map[IsBoolean:false value:{employees 0xc000190cc0 0xc000190cc0 <nil>}] map[IsBoolean:false value:{map[match:{letters 0xc000190e10 0xc000190e10 <nil>}]}] map[IsBoolean:false value:ten] map[IsBoolean:false value:10] map[IsBoolean:false value:{789000000 63729635696 <nil>}] map[IsBoolean:false value:{1 0xc000190fc0 0xc000190fc0 <nil>}]]

try
{
    Value result = await client.Query(
        Map(
            Arr(
                Arr("array"),
                true,
                false,
                BytesV.Of(0x1, 0x2, 0x3, 0x4),
                Arr(0x1, 0x2, 0x3, 0x4),
                Collection("Letters"),
                Ref("credentials/self"),
                Database("child_db"),
                Date("2019-11-12"),
                Ref(Collection("Letters"), 123),
                10.1,
                Function("double"),
                Index("letters"),
                10,
                Ref(Keys(), "1"),
                Query(Lambda("x", Var("x"))),
                null,
                Obj("x", 10),
                Role("employees"),
                Match(Index("letters")),
                "ten",
                "10",
                Time("2020-07-06T12:34:56.789Z"),
                Ref(Tokens(), "1")
            ),
            Lambda(
                "x",
                Obj(
                    "value", Var("x"),
                    "IsBoolean", IsBoolean(Var("x"))
                )
            )
        )
    );

    Console.WriteLine(result);
}
catch (Exception e)
{
    Console.WriteLine($"ERROR: {e.Message}");
}

Arr(ObjectV(value: Arr(StringV(array)),IsBoolean: BooleanV(False)), ObjectV(value: BooleanV(True),IsBoolean: BooleanV(True)), ObjectV(value: BooleanV(False),IsBoolean: BooleanV(True)), ObjectV(value: BytesV(0x01, 0x02, 0x03, 0x04),IsBoolean: BooleanV(False)), ObjectV(value: Arr(LongV(1), LongV(2), LongV(3), LongV(4)),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "Letters", collection = RefV(id = "collections")),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "295434723823452672", collection = RefV(id = "credentials")),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "child_db", collection = RefV(id = "databases")),IsBoolean: BooleanV(False)), ObjectV(value: FaunaDate(2019-11-12 12:00:00 AM),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "123", collection = RefV(id = "Letters", collection = RefV(id = "collections"))),IsBoolean: BooleanV(False)), ObjectV(value: DoubleV(10.1),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "double", collection = RefV(id = "functions")),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "letters", collection = RefV(id = "indexes")),IsBoolean: BooleanV(False)), ObjectV(value: LongV(10),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "1", collection = RefV(id = "keys")),IsBoolean: BooleanV(False)), ObjectV(value: QueryV(System.Collections.Generic.Dictionary`2[System.String,FaunaDB.Query.Expr]),IsBoolean: BooleanV(False)), ObjectV(value: NullV,IsBoolean: BooleanV(False)), ObjectV(value: ObjectV(x: LongV(10)),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "employees", collection = RefV(id = "roles")),IsBoolean: BooleanV(False)), ObjectV(value: SetRefV(System.Collections.Generic.Dictionary`2[System.String,FaunaDB.Types.Value]),IsBoolean: BooleanV(False)), ObjectV(value: StringV(ten),IsBoolean: BooleanV(False)), ObjectV(value: StringV(10),IsBoolean: BooleanV(False)), ObjectV(value: FaunaTime(2020-07-06T12:34:56.789Z),IsBoolean: BooleanV(False)), ObjectV(value: RefV(id = "1", collection = RefV(id = "tokens")),IsBoolean: BooleanV(False)))

Map(
  [
    ['array'],
    true,
    false,
    new Uint8Array([1, 2, 3, 4]),
    [0x1, 0x2, 0x3, 0x4],
    Collection('Letters'),
    Ref('credentials/self'),
    Database('child_db'),
    Date('2019-11-12'),
    Ref(Collection('Letters'), 123),
    10.1,
    Function('double'),
    Index('letters'),
    10,
    Ref(Keys(), '248967241620521472'),
    Query(Lambda('x', Var('x'))),
    null,
    { x: 10 },
    Role('employees'),
    Match(Index('letters')),
    'ten',
    '10',
    Time('2020-07-06T12:34:56.789Z'),
    Ref(Tokens(), '249062079147803136'),
  ],
  Lambda('x', {
    value: Var('x'),
    IsBoolean: IsBoolean(Var('x')),
  })
)

[
  { value: [ 'array' ], IsBoolean: false },
  { value: true, IsBoolean: true },
  { value: false, IsBoolean: true },
  { value: { '0': 1, '1': 2, '2': 3, '3': 4 }, IsBoolean: false },
  { value: [ 1, 2, 3, 4 ], IsBoolean: false },
  { value: Collection("Letters"), IsBoolean: false },
  { value: Ref(Credentials(), "302043979982045696"), IsBoolean: false },
  { value: Database("child_db"), IsBoolean: false },
  { value: Date("2019-11-12"), IsBoolean: false },
  { value: Ref(Collection("Letters"), "123"), IsBoolean: false },
  { value: 10.1, IsBoolean: false },
  { value: Function("double"), IsBoolean: false },
  { value: Index("letters"), IsBoolean: false },
  { value: 10, IsBoolean: false },
  { value: Ref(Keys(), "248967241620521472"), IsBoolean: false },
  { value: Query(Lambda("x", Var("x"))), IsBoolean: false },
  { value: null, IsBoolean: false },
  { value: { x: 10 }, IsBoolean: false },
  { value: Role("employees"), IsBoolean: false },
  { value: Match(Index("letters")), IsBoolean: false },
  { value: 'ten', IsBoolean: false },
  { value: '10', IsBoolean: false },
  { value: Time("2020-07-06T12:34:56.789Z"), IsBoolean: false },
  { value: Ref(Tokens(), "249062079147803136"), IsBoolean: false }
]

Query metrics:

bytesIn: 636
bytesOut: 1,640
computeOps: 2
readOps: 0
writeOps: 0
readBytes: 373
writeBytes: 0
queryTime: 23ms
retries: 0

This query operates on a pre-existing schema, which is not provided here.

Also, the query is executed via a client connection, that uses a secret acquired by calling the Login function (not shown here), so that Ref("credentials/self") returns a valid value.

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IsBoolean

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Parameters

Returns

Examples

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`IsBoolean`