Using Caché ObjectScript - InterSystems Documentation

Arithmetic Operators
5.2.7 Exponentiation Operator (**)
The Exponentiation Operator produces the exponentiated value of the left operand raised to the power of the right operand.
• 0**0: Zero raised to the power of zero is 0. However, if either operand is an IEEE double-precision number, (for
example, 0**$DOUBLE(0) or $DOUBLE(0)**0) zero raised to the power of zero is 1. For further details, refer to
the $DOUBLE function.
• 0**n: 0 raised to the power of any positive number n is 0. This includes 0**$DOUBLE("INF"). Attempting to raise
0 to the power of a negative number results in an error: Caché negative numbers generate an
error; $DOUBLE negative numbers generate a error.
• num**0: Any non-zero number (positive or negative) raised to the power of zero is 1. This includes
$DOUBLE("INF")**0.
• 1**n: 1 raised to the power of any number (positive, negative, or zero) is 1.
• -1**n: -1 raised to the power of zero is 1. -1 raised to the power of 1 or -1 is -1. For exponents larger than 1, see
below.
• num**n: A positive number (integer or fractional) raised to any power (integer or fractional, positive or negative)
returns a positive number.
• -num**n: A negative number (integer or fractional) raised to the power of an even integer (positive or negative)
returns a positive number. A negative number (integer or fractional) raised to the power of an odd integer (positive or
negative) returns a negative number.
• -num**.n: Attempting to raise a negative number to the power of a fractional number results in an error.
• $DOUBLE("INF")**n: An infinite number (positive or negative) raised to the power of 0 is 1. An infinite number
(positive or negative) raised to the power of any positive number (integer, fractional, or INF) is INF. An infinite
number (positive or negative) raised to the power of any negative number (integer, fractional, or INF) is 0.
• $DOUBLE("NAN"): NAN on either side of the exponentiation operator always returns NAN, regardless of the value
of the other operand.
Very large exponents may result in overflow and underflow values:
• num**nnn: A positive or negative number greater than 1 with a large positive exponent value (such as 9**153 or
-9.2**152) generates a error.
• num**-nnn: A positive or negative number greater than 1 with a large negative exponent value (such as 9**-135
or -9.2**-134) returns 0.
• .num**nnn: A positive or negative number less than 1 with a large positive exponent value (such as .22**196 or
-.2**184) returns 0.
• .num**-nnn: A positive or negative number less than 1 with a large negative exponent value (such as .22**-196
or -.2**-184) generates a error.
An exponent that exceeds the maximum value supported by Caché numbers either issues a error or
automatically converts to an IEEE double-precision floating point number. This automatic conversion is specified by using
either the TruncateOverflow() method of the %SYSTEM.Process class on a per-process basis, or the TruncateOverflow
property of the Config.Miscellaneous class on a system-wide basis. For further details, refer to the $DOUBLE function.
The following examples performs exponentiation on two numeric literals:
Write "9 ** 2 = ",9 ** 2,! // 81
Write "9 ** -2 = ",9 ** -2,! // .01234567901234567901
Write "9 ** 2.5 = ",9 ** 2.5,! // 242.9999999994422343
Using Caché ObjectScript 39