Logical functions

These functions provide convenient one-line methods for evaluating expressions. They include methods for checking for empty values, using if-else logic, and implementing switch-case statements among others.

Boolean

Boolean(value) -> Boolean

Function bundle: Core

Attempts to convert the given non-boolean value to a boolean value. For example a text value of 'true' would become true.

Parameter

• value: Text | Number - A text or number value to be converted to a boolean.

Return value: Boolean

Examples

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// returns `true`
Boolean('true')

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// returns `false`. A value of 1 would return `true`
Boolean(0)

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// returns `false`
Boolean('hello')

Decode

Decode(expression, [compare1, return1, ..., compareN, returnN]?, default?) -> Any

Function bundle: Core

Evaluates an expression to a value and compares the result value with the value of subsequent parameters. If the expression evaluates to a matching value, it returns the subsequent parameter value. If no matches are found, then a default value may be provided. This is similar to a switch/case statement

Parameters

• expression: Any - An Arcade expression that must evaluate to a value that can be compared with the provided case values.
• [compare1, return1, ..., compareN, returnN] (Optional): Any - A set of compare values and return value pairs.
• default (Optional): Any - A default value to return if none of the compare values match. This may be a value of any type.

Return value: Any
Returns the matched return value. If no matches are found, then the default value is returned.

Example

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// returns a meaningful value when a field contains coded values
var code = $feature.codedValue;
var decodedValue = Decode(code, 1, 'Residential', 2, 'Commercial', 3, 'Mixed', 'Other');

DefaultValue

DefaultValue(value, defaultValue) -> Any

Function bundle: Core

Returns a specified default value if an empty value is detected.

Parameters

• value: Any - The input value to compare against null or ''. This may be a value of any type. However, if this value is an empty array, then the empty array will be returned.
• defaultValue: Any - Return this value if the provided value is empty. The data type of defaultValue must match the data type of value.

Return value: Any
If value is empty, then the defaultValue is returned. Otherwise, the value of value is returned.

Example

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// If a feature has no value in the POP_2000 field
// then 'no data' is returned
DefaultValue($feature.POP_2000, 'no data')

IIf

IIf(condition, trueValue, falseValue) -> Any

Function bundle: Core

Returns a given value if a conditional expression evaluates to true, and returns an alternate value if that condition evaluates to false.

Parameters

• condition: Boolean - A logical expression that must evaluate to true or false.
• trueValue: Any - The value to return if the condition evaluates to true. This may be a value of any type.
• falseValue: Any - The value to return if the condition evaluates to false. This may be a value of any type.

Return value: Any
If condition is true, then the trueValue is returned. Otherwise, the value of falseValue is returned.

Example

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// returns 'below' if the value is less than 1,000,000.
// if the value is more than 1,000,000, then returns 'above'
var population = $feature.POP_2007;
IIf(population < 1000000, 'below', 'above');

IsEmpty

IsEmpty(value) -> Boolean

Function bundle: Core

Returns true if the provided value is null or an empty text (e.g. ''). Returns false for all other cases, including empty arrays and dictionaries.

Parameter

• value: Any - The value that is compared against null or ''. This may be a value of any type.

Return value: Boolean

Examples

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// Returns true
IsEmpty(null)

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// Returns false
IsEmpty('hello world')

IsNan

IsNan(value) -> Boolean

Since version 1.5

Function bundle: Core

Indicates whether the input value is not a number (NaN). A number is considered NaN in one of the following scenarios: - 0/0 - Infinity / Infinity - Infinity * 0 - Any operation in which NaN is an operand - Casting a non-numeric text or undefined to a number

Parameter

• value: Any - The value to check if it is NaN.

Return value: Boolean

Examples

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// Returns true
IsNan(Infinity / Infinity)

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// Returns false
IsNan('4')

TypeOf

TypeOf(value) -> Text

Function bundle: Core

Returns the type of the input value. Will return one of the following types: Array, Date, Text, Boolean, Number, Dictionary, Feature, FeatureSet, Point, Polygon, Polyline, Multipoint, Extent, Function, Unrecognized Type.

Parameter

• value: Any - The input value, variable, or feature attribute.

Return value: Text

Examples

prints 'Boolean'

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TypeOf(true)

prints 'Date'

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TypeOf(Now())

When

When(expression1, result1, [expression2, result2, ..., expressionN, resultN]?, defaultValue) -> Any

Function bundle: Core

Evaluates a series of conditional expressions until one evaluates to true.

Parameters

• expression1: Boolean - a conditional expressions, if it evaluates to true then result1 will be returned.
• result1: Any - The result returned if the expression1 evaluates to true. This may be a value of any type.
• [expression2, result2, ..., expressionN, resultN] (Optional): Any - A series of conditional expressions and return values if the given expression evaluates to true. This may be a value of any type.
• defaultValue: Any - Returns this value if all expressions evaluate to false. This may be a value of any type.

Return value: Any

Example

Reclassify a numeric field value to a generic ranking (text).
If all expressions are false, then 'n/a' is returned

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var density = $feature.densityField;
var ranking = When(density < 50, 'low', density >=50 && density < 100, 'medium', density >= 100, 'high', 'n/a');