COMP-2 | COMPUTATION-2

Tip! COMP-2 applies to the Numeric Data type.

COMP-2 is a USAGE type that stores numbers as internal double-precision (64-bit) floating-point. It allows a VALUE clause with a signed floating-point.

Storage Size and Format -

COMP-2 has no PICTURE clause and is 8 bytes long (DOUBLE WORD). COMP-2 data is stored in the format of mantissa and exponent.

Digits in PICTURE clause	Storage occupied
1 through 32	8 bytes (DOUBLE WORD)

Using -

Floating-point numbers are real numbers - For example -, 9.99, 99, etc.

Definition in a COBOL Program -

To define a COMP-2 variable in COBOL program, we use the USAGE IS COMP-2 clause in the DATA DIVISION. For example -

01 WS-DFPN     USAGE IS COMP-2.

In this example, WS-DFPN is a variable holding a double-precision floating-point number using 8 bytes of storage.

Assigning Values to a COMP-2 Variable -

We can assign values to a COMP-2 variable like any other numeric variable in COBOL. For example -

MOVE 9.999 TO WS-DFPN.

The 9.999 value is stored in a variable declared COMP-2. The data is stored in memory like .9999 * 10E 1. 9.999 is equal to .9999 * 10E 1. In the above, 1 is the exponent value, and .9999 is the mantissa.

Arithmetic Operations -

Like other numeric variables, we can perform all arithmetic operations (add, subtract, multiply, divide, etc.) on COMP-2 variables. For example -

ADD 10.5 TO WS-DFPN.

Range of Values -

COMP-2 can represent values in the approximate range of ±2.23 x 10^-308 to ±1.80 x 10^308.

Practical Example -

Scenario - Defining, initializing, its usage and display of COMP-2 variables.

Code -

Full Example

----+----1----+----2----+----3----+----4----+----5----+
       ...
       WORKING-STORAGE SECTION.
       01 WS-VAR.
          05 WS-PI           USAGE IS COMP-2.
          05 WS-RADIUS       USAGE IS COMP-2. 
          05 WS-AREA         USAGE IS COMP-2. 
       ...
       PROCEDURE DIVISION. 

           MOVE 3.1415927          TO WS-PI. 
           MOVE 10                 TO WS-RADIUS.  
           COMPUTE WS-AREA = WS-PI * (WS-RADIUS ** 2). 

           DISPLAY "THE AREA OF THE CIRCLE: " WS-AREA.
           ...

Output -

THE AREA OF THE CIRCLE:  .31415926999999994E 03