Datatype functions

Revision as of 00:15, 5 November 2015 by Bbecane (talk | contribs)


A value can be a number, text, Null, or a reference. Integers, reals, Boolean, and date values, are all represented as numbers. You can use these functions from the Special library of Definition menu to determine the type.

IsNumber(x): Returns True if x is a number, including a boolean, date, INF, NAN, or complex.

IsNumber(0) → True
IsNumber(False) → True
IsNumber(INF) → True
IsNumber('hi') → False
IsNumber(5) → True
IsNumber('5') → False
IsNumber(NAN) → True

IsText(x): Returns True if x is a text value.

IsText('hello') → True
IsText(7) → False
IsText('7') → True

IsNaN(x): Returns True if x is “not a number,” i.e., NAN. INF or regular numbers do not qualify, nor does a text or Null.

0/0 → NAN
IsNaN(0/0) → True
IsNaN(5) → False
IsNaN(INF) → False
IsNaN('Hello') → False

IsNull(x): To test if x is exactly Null. Returns false if x is an array.

x = NULL: To test if an atomic x is Null. When x is an array, returns True or False for each element of the array.

IsUndef(x): Returns True if atomic x is Nullor the internal value Undefined (usually indicating uncomputed). When x is an array, returns True or False for each element of the array.

IsRealNumber(x): Returns True when x is a real number, including a boolean, date or INF. Returns False when x is a complex number or NAN.

IsReference(x): Returns True if x is a reference to a value.

IsHandle(x): Returns True if x is a handle to an Analytica object.

TypeOf(x): Returns the type of expression x as a text value, usually one of Number, Text, Reference, or Null. INF and NAN are both of type "Number":

TypeOf(2008) → "Number"
TypeOf('2008') → "Text"
TypeOf(INF) → "Number"
TypeOf(0/0) → "Number"

See Also

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