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Type Functions

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    Type functions perform operations that check or convert expressions.

    Type-Checking Functions

    ISARRAY(expression)

    Returns True if expression is an array, otherwise returns MISSING, NULL or false.

    ISATOM(expression)

    Returns True if expression is a Boolean, number, or string, otherwise returns MISSING, NULL or false.

    ISBOOLEAN(expression)

    Returns True if expression is a Boolean, otherwise returns MISSING, NULL or false.

    ISNUMBER(expression)

    Returns True if expression is a number, otherwise returns MISSING, NULL or false.

    ISOBJECT(expression)

    Returns True if expression is an object, otherwise returns MISSING, NULL or false.

    ISSTRING(expression)

    Returns True if expression is a string, otherwise returns MISSING, NULL or false.

    TYPE(expression)

    Returns one of the following strings, based on the value of expression:

    • "missing"

    • "null"

    • "boolean"

    • "number"

    • "string"

    • "array"

    • "object"

    • "binary"

    Type-Conversion Functions

    TOARRAY(expression)

    Returns array as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • Arrays are themselves.

    • All other values are wrapped in an array.

    TOATOM(expression)

    Returns atomic value as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • Arrays of length 1 are the result of TOATOM() on their single element.

    • Objects of length 1 are the result of TOATOM() on their single value.

    • Booleans, numbers, and strings are themselves.

    • All other values are NULL.

    TOBOOLEAN(expression)

    Returns Boolean as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • False is false.

    • Numbers +0, -0, and NaN are false.

    • Empty strings, arrays, and objects are false.

    • All other values are true.

    TONUMBER(expression)

    Returns number as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • False is 0.

    • True is 1.

    • Numbers are themselves.

    • Strings that parse as numbers are those numbers.

    • All other values are NULL.

    TOOBJECT(expression)

    Returns object as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • Objects are themselves.

    • All other values are the empty object.

    TOSTRING(expression)

    Returns string as follows:

    • MISSING is MISSING.

    • NULL is NULL.

    • False is "false".

    • True is "true".

    • Numbers are their string representation.

    • Strings are themselves.

    • All other values are NULL.