iTS 1.0+)

SCREEN COBOL Source Program

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

2-20

Simple Conditions

Relation Condition

A relation condition causes a comparison of two values. Each value can be a data item,

a literal, or a value resulting from an arithmetic computation; both values cannot be

literals. A relation condition has a truth value of true if the relation exists between the

values.

Relation condition syntax is:

The relational operators <, =, > (less than, equal to, greater than) determine the type of

comparison made. A space must precede and follow each word of the relational

operator. When NOT is included, the word NOT and the next keyword or relation

character are one operator. NOT EQUAL is a truth test for an unequal comparison;

NOT GREATER is a truth test for an equal or less comparison.

Two numeric values can be compared regardless of their usage (as defined by a USAGE

clause). For all other comparisons, however, the values must have the same usage. If

either of the values is a group item, nonnumeric comparison rules apply.

Comparison of Numeric Operands

Comparison of numeric operands is made with respect to the algebraic value of the

operands. The length of the literal or arithmetic expression operands, in terms of the

number of digits represented, is not significant. Zero is considered a unique value

regardless of the sign.

Comparison of these operands is permitted regardless of the manner in which their usage

is described. Unsigned numeric operands are considered positive.

Comparison of Nonnumeric Operands

Comparison of nonnumeric operands, or one numeric and one nonnumeric operand, is

made with respect to the ASCII collating sequence of characters. The size of an operand

is its total number of characters.

A noninteger numeric operand cannot be compared to a nonnumeric operand.

Numeric and nonnumeric operands can be compared only when their usage is the same.

The following conventions apply:

•

The numeric operand must be an integer data item or an integer literal.

•

If the nonnumeric operand is an elementary data item or a nonnumeric literal, the

numeric operand is treated as though it were moved to an elementary alphanumeric

value-1 IS { [ NOT ] { LESS [ THAN ] } } value-2

{ { < } }

{ }

{ [ NOT ] { EQUAL [ TO ] } }

{ { = } }

{ }

{ [ NOT ] { GREATER [ THAN ] } }

{ { > } }