6.1.5.1 "COBOL Language Reference" IBM Library Server

6.1.5.1 Arithmetic Operators

Five binary arithmetic operators and two unary arithmetic operators (Table 15) can be used in arithmetic expressions. They are represented by specific characters that must be preceded and followed by a space.

Binary Operator	Meaning	Unary Operator	Meaning

Table 15. Binary and Unary Operators
+	Addition	+	Multiplication by +1
-	Subtraction	-	Multiplication by -1
*	Multiplication
/	Division
**	Exponentiation

Note: Exponents in fixed-point exponential expressions cannot contain more than 9 digits. The compiler will truncate any exponent with more than 9 digits. In this case, the compiler will issue a diagnostic message if the exponent is a literal or constant; if the exponent is a variable or data-name, a diagnostic is issued at run-time.

Parentheses can be used in arithmetic expressions to specify the order in which elements are to be evaluated.

Expressions within parentheses are evaluated first. When expressions are contained within a nest of parentheses, evaluation proceeds from the least inclusive to the most inclusive set.

When parentheses are not used, or parenthesized expressions are at the same level of inclusiveness, the following hierarchic order is implied:

Unary operator
Exponentiation
Multiplication and division
Addition and subtraction.

Parentheses either eliminate ambiguities in logic where consecutive operations appear at the same hierarchic level or modify the normal hierarchic sequence of execution when this is necessary. When the order of consecutive operations at the same hierarchic level is not completely specified by parentheses, the order is from left to right.

An arithmetic expression can begin only with a left parenthesis, a unary operator, or an operand (that is, an identifier or a literal). It can end only with a right parenthesis or an operand. An arithmetic expression must contain at least one reference to an identifier or a literal.

There must be a one-to-one correspondence between left and right parentheses in an arithmetic expression, with each left parenthesis placed to the left of its corresponding right parenthesis.

If the first operator in an arithmetic expression is a unary operator, it must be immediately preceded by a left parenthesis if that arithmetic expression immediately follows an identifier or another arithmetic expression.

Table 16shows permissible arithmetic symbol pairs. An arithmetic symbol pair is the combination of two such symbols in sequence. In the table:

Yes

indicates a permissible pairing.

No

indicates that the pairing is not permitted.

First Symbol	Identifier or Literal	* / ** + -	Unary + or Unary -	(	)

Table 16. Valid Arithmetic Symbol Pairs
First Symbol	Second Symbol
Identifier or Literal	No	Yes	No	No	Yes
* / ** + -	Yes	No	Yes	Yes	No
Unary + or Unary -	Yes	No	No	Yes	No
(	Yes	No	Yes	Yes	No
)	No	Yes	No	No	Yes

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6.1.5.1 Arithmetic Operators

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