Conditional Expressions › General Considerations

General Considerations

Contents

Conditional expressions can contain:

• A single test condition
• Two or more test conditions combined with the logical operators AND and OR
• The logical operator NOT to specify the opposite of the condition

  NOT can precede a single condition or a compound condition enclosed in parentheses.

Evaluation of Operators

Operators in a conditional expression are evaluated one at a time, from left to right, in the following order of precedence:

• Unary plus or minus
• Multiplication or division
• Addition or subtraction
• MATCHES or CONTAINS keywords
• EQ, NE, GT, LT, GE, LE operators
• NOT
• AND
• OR

The default order of precedence can be overridden by using parentheses. The expression in the innermost parentheses is evaluated first.

Significant tests in conditional expressions should be coded to the left for greater runtime efficiency.