Easytrieve Operator Cheat Sheet

Relational Operators

Relational operators compare two values in IF, DO WHILE, and similar expressions. They return true or false for the condition. Numeric fields compare by numeric value; alphanumeric fields compare by character sequence (collating sequence on mainframe). Mixed-type compares follow Language Reference conversion rules—prefer explicit types in DEFINE and FILE to avoid surprises.

Logical Operators

Logical operators combine multiple conditions. AND requires all parts true. OR requires at least one part true. NOT inverts a condition. Complex filters use parentheses where your release supports grouping—document non-obvious logic in comments. Short-circuit behavior may differ by release; do not rely on side effects in unused branches.

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IF DEPT EQ 911 AND GROSS GT 50000
   PRINT HIGH-PAY-RPT
END-IF
 
IF REGION EQ 'E' OR REGION EQ 'W'
   PERFORM REGION-TOTAL
END-IF

Assignment and MOVE

MOVE copies from source to target. Assignment statements may use = in some expression contexts per release. Watch length—moving long alphanumeric to shorter field truncates. Moving numeric to alphanumeric may require edit masks or conversion. Multiple targets can sometimes receive the same source in one statement depending on grammar. See assignment and MOVE tutorials for COBOL migration differences.

Arithmetic Operators

Addition, subtraction, multiplication, and division appear in assignment expressions and ADD statements. Packed decimal fields preserve scale when defined with decimals. Division by zero causes runtime errors—guard with IF. Rounding follows packed rules; financial apps document half-up expectations in comments.

Special Comparisons

Operator Precedence (Practical Rules)

1. Parentheses group conditions when supported—use for clarity even if optional.
2. NOT applies to nearest condition—use parentheses for NOT (A AND B) intent.
3. AND often binds tighter than OR—verify complex expressions with compile listing tests.
4. When in doubt, split into nested IF blocks—readability beats clever one-liners.

Common Operator Mistakes

• Using = for comparison where grammar requires EQ word form in some contexts.
• Comparing packed to alphanumeric without conversion.
• IF DEPT EQ 911 versus EQ '911'—numeric versus character DEPT type.
• Forgetting NOT EOF before GET in manual read loops.
• MOVE truncating keys used later in SORT or match logic.

Per-Operator Tutorial Links

Deep dives: EQ, NE, GT, LT, GE, LE, AND, OR, NOT, MOVE, assignment under /operators/ in this tutorial. Use those pages for migration quirks and report writer interactions.

Explain It Like I'm Five

Operators are question words and actions. EQ asks are these the same? GT asks is this bigger? AND means both questions must be yes. MOVE means copy this sticker to that box. The cheat sheet is the small card on the desk so you do not forget the question words while doing homework.

Exercises

1. Write IF with AND filtering department and minimum pay.
2. Rewrite one IF using OR instead of two separate IFs—when equivalent?
3. Write NOT EOF test before a GET loop pseudocode.
4. Identify type mismatch risk in IF comparing N field to quoted literal.
5. List relational operators and one payroll example for each.