Examine - Inspecting

Enhanced Definition

`EXAMINE` and `INSPECT` are COBOL verbs used to analyze and manipulate character strings within data items. `INSPECT` is the modern, more powerful successor to the older `EXAMINE` verb, providing advanced capabilities for counting occurrences of specific characters or strings, and replacing them.

Key Characteristics

- INSPECT verb:
- Provides capabilities for TALLYING (counting) and REPLACING characters or strings within an alphanumeric or national data item.
- Supports ALL, LEADING, and FIRST options for specifying which occurrences to count or replace.
- Allows for conditional processing using BEFORE INITIAL and AFTER INITIAL phrases, limiting the scope of the operation.
- Can operate on both single characters and character strings.
- EXAMINE verb (Legacy):
- An older COBOL verb, largely superseded by INSPECT.
- Primarily used for counting and replacing single characters within alphanumeric data items only.
- Less flexible and powerful than INSPECT, lacking string replacement and conditional processing options.
- Its use is generally discouraged in modern COBOL development.

Use Cases

- Data Cleansing: Removing unwanted leading/trailing spaces, special characters, or converting specific characters (e.g., changing all hyphens to spaces in a product code).
- Data Validation: Checking if an input field contains only numeric characters, alphabetic characters, or a specific set of allowed characters.
- Character Counting: Determining the number of occurrences of a specific character (e.g., commas in a delimited string) for parsing or analysis.
- String Transformation: Masking sensitive data by replacing certain characters with asterisks or other placeholder characters.
- Formatting: Ensuring consistent data formats by replacing inconsistent delimiters or converting character cases (though INSPECT doesn't directly handle case conversion, it can be part of a larger routine).

Related Concepts

INSPECT and EXAMINE are fundamental COBOL verbs for character-level string manipulation, operating directly on PIC X (alphanumeric) and PIC N (national) data items defined in the DATA DIVISION. They are often used in conjunction with MOVE statements to prepare data for processing or display, and with IF statements for conditional logic based on the results of the inspection. While modern COBOL offers intrinsic functions for some string operations (e.g., TRIM, REPLACE), INSPECT remains a powerful and widely used verb for complex, character-by-character analysis and replacement, especially in performance-critical batch applications on z/OS.

Best Practices:

Prioritize INSPECT for New Development: Always use the INSPECT verb for any new string manipulation logic due to its enhanced capabilities, flexibility, and adherence to modern COBOL standards. EXAMINE should only be encountered when maintaining very old legacy code.
Utilize BEFORE/AFTER INITIAL: Employ these phrases to precisely define the portion of the data item to be inspected, improving efficiency and preventing unintended modifications.
Understand ALL, LEADING, FIRST: Carefully select the appropriate option (ALL, LEADING, or FIRST) based on whether you need to process all occurrences, only leading occurrences, or just the first occurrence of a character/string.
Test Edge Cases Thoroughly: String manipulation can be prone to errors; rigorously test INSPECT statements with various scenarios, including empty strings, strings with no matches, and strings where the target character/string appears at the beginning, middle, and end.
Consider Intrinsic Functions for Simplicity: For simpler tasks like trimming spaces or basic replacements, COBOL intrinsic functions (e.g., FUNCTION TRIM, FUNCTION REPLACE) might offer more concise and readable code, but INSPECT remains superior for complex, conditional character processing.