Predicate function - Object

The object functions validate object existence, types, and perform comparisons.

Comparison predicates use type‑strict evaluation unless explicitly documented otherwise.
Unless otherwise stated, range comparisons are inclusive of the minimum and maximum values.

Function	Description	Example
IsDefined(value)	Returns true if the value is defined.	"hello" is true false is true NaN is true null is false undefined is false
IsUndefined(value)	Returns true if the value is undefined (or null in contexts where undefined doesn't exist).	undefined is true null is true All defined values is false
IsNull(value)	Returns true if the value is null.	null is true All other values is false
IsNotNull(value)	Returns true if the value is not null.	All values except null is true null is false
IsNullOrUndefined(value)	Returns true if the value is null or undefined.	null is true undefined is true All other values is false
IsType(value, type)	Returns true if the value is of a specified type using type object/constructor.	IsType(123, typeof(int)) is true IsType(new Date(), Date) is true IsType(null, "string") is false
IsType(value, typeName)	Returns true if the value matches a specified type using type name string.	IsType("hello", "string") is true IsType([], "Array") is true IsType(123, "string") is false
Equals(value1, value2)	Returns true if value1 and value2 are equal.	Equals(5, 5) is true Equals({a: 1}, {a: 1}) is true Equals(5, 6) is false
NotEquals(value1, value2)	Returns true if value1 and value2 not equal.	NotEquals(4, 6) is true NotEquals(4, 4) is false
IsOneOf(value, ...options)	Returns true if the value matches any of the specified options.	IsOneOf(5, 1, 2, 3, 4, 5) is true IsOneOf(5, 1, 2, 3, 4) is false
IsOneOf(value, options)	Returns true if the value matches any value in the provided collection of options.	IsOneOf("red", "red, green, blue") is true IsOneOf(5, "1, 2, 3, 4,5") is true IsOneOf(6, "[1,2,3,4,5,6]") is true IsOneOf("yellow", "red,green,blue") is false
IsNotOneOf(value, ...options)	Returns true if the value does not match any of the specified options.	IsNotOneOf(6, 1,2,3,4,5) is true IsNotOneOf(5, 1,2,3,4,5) is false
IsNotOneOf(value, options)	Returns true if the value does not match any value in the provided collection of options.	IsNotOneOf(5, "1, 2, 3, 4") is true IsNotOneOf(5, "[2, 5, 6]") is true IsNotOneOf(true, "true,false") is false
IsBetween(value, min, max)	Returns true if the number is between the minimum and the maximum range (inclusive).	IsBetween(5, 1, 10) is true IsBetween(new Date(2023,5,15), new Date(2023,0,1), new Date(2023,11,31)) is true IsBetween(11, 1, 10) is false