iTS 1.0+)

SCREEN COBOL Source Program

Compaq NonStop™ Pathway/iTS SCREEN COBOL Reference Manual—426750-001

2-21

Complex Conditions

data item of the same size as the numeric data item; the content of this

alphanumeric data item is then compared to the nonnumeric operand.

•

If the nonnumeric operand is a group item, the numeric operand is treated as though

it were moved to a group item of the same size as the numeric data item; the content

of this group item is then compared to the nonnumeric operand.

Comparison of Equal-Sized Operands

If the values of operands are equal in size, characters in corresponding positions are

compared starting from the high order end. The comparison continues until either a pair

of unequal characters is found or the low order end is reached. The values are equal

when all pairs of characters are the same.

The first pair of unequal characters is compared to determine their relative position in

the collating sequence. The value having the character that is higher in the collating

sequence is the greater value.

Comparison of Unequal-Sized Operands

If the values of operands are unequal in size, comparison proceeds as though the shorter

operand were extended on the right by sufficient spaces to make the operands equal in

size.

Sign Condition

The sign condition determines whether or not the algebraic value of an arithmetic

expression is greater than, less than, or equal to zero.

Sign condition syntax is:

arithmetic-expression must have at least one variable.

When NOT is included, the word NOT and the next keyword specify one sign condition

that defines the algebraic test to be executed for truth value. NOT ZERO is a truth test

for a nonzero, positive, or negative value. An item is positive if its value is greater than

zero, negative if its value is less than zero, and zero if its value is equal to zero.

Complex Conditions

Complex conditions are formed by using simple conditions, combined conditions and/or

complex conditions with logical connectives AND or OR, or by negating these

conditions with the keyword NOT. The truth value of a complex condition, whether or

not the value is enclosed in parentheses, is that truth value which results from the

interaction of all the logical operators on the individual truth values of simple

conditions, or on the intermediate truth values of conditions connected or negated.

Table 2-9

lists and defines the logical operators.

arithmetic-expression [ IS ] [ NOT ] { POSITIVE }

{ NEGATIVE }

{ ZERO }