The Main Difference Between COBOL 77 And COBOL 88 You Should Know

Dispatch 13 Jun 2024

COBOL, short for COmmon Business-Oriented Language, is a programming language that was designed specifically for business applications. When it was first created in 1959, it was one of the first programming languages ever developed. COBOL is still widely used today, especially for legacy systems.

Two of the most important data types in COBOL are the 77 level and the 88 level. The 77 level is used to define elementary data items, while the 88 level is used to define group data items.

The main difference between the 77 level and the 88 level is that the 77 level can only contain one data item, while the 88 level can contain multiple data items. This makes the 88 level more useful for defining complex data structures.

Here is an example of a 77 level data item:

01 name PIC X(30).

This data item defines a character string that can be up to 30 characters long.

Here is an example of an 88 level data item:

01 address. 05 street-address PIC X(30). 05 city PIC X(20). 05 state PIC X(2). 05 zip-code PIC X(5).

This data item defines a complex data structure that contains four different data items: a street address, a city, a state, and a zip code.

The 77 level and the 88 level are two of the most important data types in COBOL. They are used to define both simple and complex data structures.

Difference 77 and 88 COBOL

In COBOL, the 77 level and 88 level are two important data types used to define data items. The 77 level is used to define elementary data items, while the 88 level is used to define group data items.

Data type: The 77 level can only contain one data item, while the 88 level can contain multiple data items.
Usage: The 77 level is used to define simple data items, such as a name or a date, while the 88 level is used to define complex data structures, such as an address or a customer record.
Syntax: The 77 level is defined using the PIC clause, while the 88 level is defined using the VALUE clause.
Scope: The 77 level can be used anywhere in a COBOL program, while the 88 level can only be used in the Data Division.
Performance: The 77 level is more efficient than the 88 level, because it requires less memory and processing time.

The 77 level and the 88 level are two of the most important data types in COBOL. They are used to define both simple and complex data structures, and they play a vital role in the development of COBOL programs.

Data type

This is one of the key differences between the 77 level and the 88 level in COBOL. The 77 level is used to define elementary data items, such as a name or a date, while the 88 level is used to define complex data structures, such as an address or a customer record.

The fact that the 77 level can only contain one data item, while the 88 level can contain multiple data items, has a significant impact on the way that COBOL programs are written. For example, if you need to store a customer's name and address, you would need to define two separate 77 level data items. However, if you use an 88 level data item, you can define a single data item that contains both the customer's name and address.

This can make your COBOL programs more efficient and easier to read. Additionally, using 88 level data items can help to reduce the amount of memory that your programs require.

Here is an example of how you would define a customer's name and address using 77 level data items:

01 customer-name PIC X(30).01 customer-address PIC X(30).

Here is an example of how you would define a customer's name and address using an 88 level data item:

01 customer. 05 customer-name PIC X(30). 05 customer-address PIC X(30).

As you can see, the 88 level data item is much more concise and easier to read than the 77 level data items.

The ability to define complex data structures is one of the most important features of COBOL. It allows COBOL programmers to create programs that are both efficient and easy to maintain.

Usage

This difference between the 77 level and the 88 level in COBOL has a significant impact on the way that COBOL programs are written.

Simple data items are typically used to store individual pieces of information, such as a customer's name or a product's price.
For example, the following 77 level data item defines a customer's name:
```
01 customer-name PIC X(30).
```
Complex data structures are used to store collections of related data items, such as a customer's address or a list of products ordered by a customer.
For example, the following 88 level data item defines a customer's address:
```
01 customer-address. 05 street-address PIC X(30). 05 city PIC X(20). 05 state PIC X(2). 05 zip-code PIC X(5).
```

By using the appropriate data type for each data item, COBOL programmers can create programs that are both efficient and easy to maintain.

Here is a summary of the key differences between the 77 level and the 88 level in COBOL:

The 77 level is used to define elementary data items, while the 88 level is used to define group data items.
The 77 level can only contain one data item, while the 88 level can contain multiple data items.
The 77 level is used to define simple data items, such as a name or a date, while the 88 level is used to define complex data structures, such as an address or a customer record.

Syntax

The syntax of the 77 level and the 88 level in COBOL is one of the key differences between the two data types. The 77 level is defined using the PIC clause, while the 88 level is defined using the VALUE clause.

PIC clause
The PIC clause is used to define the data type and length of a 77 level data item. The PIC clause can also be used to define other attributes of the data item, such as whether it is signed or unsigned, and whether it can contain decimal places.
VALUE clause
The VALUE clause is used to define the initial value of an 88 level data item. The VALUE clause can also be used to define other attributes of the data item, such as whether it is constant or variable.

The following table summarizes the key differences between the PIC clause and the VALUE clause:

| Feature | PIC clause | VALUE clause ||---|---|---|| Purpose | Defines the data type and length of a 77 level data item | Defines the initial value of an 88 level data item || Syntax | PIC <data-type>[(length)] | VALUE <value> || Usage | Required | Optional |

The PIC clause and the VALUE clause are two important clauses that are used to define 77 level and 88 level data items in COBOL. By understanding the syntax and purpose of these clauses, COBOL programmers can create programs that are both efficient and easy to maintain.

Scope

The scope of a data item refers to the parts of a COBOL program in which the data item can be used. The 77 level has a global scope, which means that it can be used anywhere in a COBOL program. The 88 level, on the other hand, has a local scope, which means that it can only be used in the Data Division of a COBOL program.

This difference in scope is due to the different purposes of the 77 level and the 88 level. The 77 level is used to define elementary data items, which are the basic building blocks of data in COBOL. Elementary data items can be used to store simple data values, such as numbers, characters, and dates.

The 88 level, on the other hand, is used to define group data items, which are collections of related elementary data items. Group data items can be used to store complex data structures, such as addresses, customer records, and inventory items.

Because elementary data items are used to store simple data values, they can be used anywhere in a COBOL program. Group data items, on the other hand, are used to store complex data structures, so they can only be used in the Data Division of a COBOL program.

The scope of the 77 level and the 88 level is an important consideration when designing COBOL programs. By understanding the scope of each data type, COBOL programmers can create programs that are both efficient and easy to maintain.

Performance

In the context of "difference 77 and 88 COBOL," the performance difference between the two data types is a significant consideration. The 77 level's superiority in efficiency stems from its simpler structure, which demands less memory and processing power compared to the 88 level.

Memory Usage
Elementary data items, defined using the 77 level, occupy less memory than group data items defined using the 88 level. This is because the 77 level does not require additional overhead for managing the group structure.
Processing Time
The simpler structure of the 77 level also contributes to faster processing times. COBOL programs can access and manipulate elementary data items more efficiently, as they do not need to navigate the hierarchical structure of group data items.

The performance benefits of the 77 level make it a more suitable choice for applications that require fast data processing and efficient memory utilization. By understanding the performance implications of the 77 and 88 levels, COBOL programmers can optimize their programs for specific requirements.

FAQs on the Difference Between 77 and 88 Level in COBOL

The 77 and 88 levels in COBOL are two distinct data types used for defining data items. Understanding their differences is crucial for effective COBOL programming.

Question 1: What is the primary difference between the 77 and 88 levels in COBOL?

The 77 level is used to define elementary data items, which can hold a single value, while the 88 level is used to define group data items, which can hold multiple related data items.

Question 2: How does the scope of 77 and 88 level data items differ?

The 77 level data items have a global scope, meaning they can be accessed from anywhere within the COBOL program. In contrast, the 88 level data items have a local scope, meaning they can only be accessed within the Data Division.

Question 3: Which data type is more efficient in terms of memory usage?

The 77 level data items are more efficient in terms of memory usage as they occupy less memory compared to 88 level data items.

Question 4: How does the processing speed differ between 77 and 88 level data items?

The 77 level data items can be processed faster than 88 level data items due to their simpler structure, which requires less processing time.

Question 5: When should I use the 77 level and when should I use the 88 level?

Use the 77 level when you need to define simple data items that can hold a single value. Use the 88 level when you need to define complex data structures that contain multiple related data items.

Question 6: What are the key takeaways regarding the difference between 77 and 88 level data items?

The 77 level is used for elementary data items with global scope and higher efficiency, while the 88 level is used for group data items with local scope. Choosing the appropriate data type is essential for optimizing COBOL program performance and maintainability.

Understanding the difference between the 77 and 88 levels in COBOL empowers programmers to create efficient, structured, and maintainable COBOL programs.

Transition to the next article section: Exploring Advanced COBOL Data Structures

Conclusion

The distinction between the 77 and 88 level data items in COBOL is a fundamental concept that plays a vital role in the efficiency and maintainability of COBOL programs. This article has explored the key differences between these two data types, providing insights into their usage, scope, and performance characteristics.

By comprehending the nuances of 77 and 88 level data items, programmers can make informed decisions when defining data structures, optimizing memory usage, and enhancing processing speed. The ability to choose the appropriate data type empowers developers to create robust and efficient COBOL applications.

As COBOL continues to evolve and adapt to modern computing environments, the understanding of data types remains a cornerstone of effective programming. Embracing the differences between 77 and 88 level data items will contribute to the development of high-quality COBOL programs that meet the demands of complex business systems.

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