Are you building robust enterprise applications with Rocket Uniface? Then you’re no stranger to managing various data types. Today, we’re diving deep into a fundamental yet often misunderstood type: the float. Grasping its nuances is key to preventing unexpected data issues in your applications.

What Exactly is a Float?

At its core, a float (short for floating-point number) is a data type designed to store numbers that include a decimal point. Unlike integers, which handle only whole numbers, floats are perfect for values like monetary amounts (e.g., 19.99), measurements (e.g., 3.14159), or scientific readings (e.g., 0.00000001).

Using Floats in Your ProcScript

Declaring and utilizing float variables within your Uniface ProcScript is straightforward. You’ll typically define them within a variables block or as parameters in a params block.

Here’s a quick example:

variables
  float v_calculationResult
  float v_itemWeight
endvariables

v_calculationResult = 12345.6789
v_itemWeight = 2.55

putmess "Our calculation yielded: %%v_calculationResult. The item weighs: %%v_itemWeight kg."

This snippet demonstrates declaring two float variables, assigning them values, and then displaying them in a user message.

Uniface’s Remarkable Internal Precision

One of Uniface’s standout features is its incredible internal precision for the float data type. It boasts a platform-independent precision of up to 38 digits for the mantissa (the significant digits of the number) and a four-digit exponent. This empowers Uniface to handle exceptionally large or infinitesimally small numbers with high accuracy, regardless of the underlying operating system.

The Crucial Database Connection: A Word of Caution!

While Uniface’s internal float precision is impressive, here’s the most critical point: the actual precision of your stored data will ultimately be governed by your database management system (DBMS).

Imagine performing a highly precise calculation in your Uniface component, yielding a result with 30 decimal places. If you then attempt to save this result into a standard FLOAT or REAL column in a SQL database, the database might round, truncate, or otherwise alter your number to fit its own, often less precise, data type.

Always verify the specific data type limitations and behaviors of your target database when designing schema and handling float values. This diligence will prevent data loss and ensure the integrity of your numerical information.

Additional Float Capabilities

• Scientific Notation Support: Uniface conveniently allows you to input float values using scientific notation. For instance, entering 6.022e23 will be correctly interpreted as 6.022 multiplied by 10 to the power of 23.
• Automatic Display Formatting: If you don’t explicitly define a display format for a float field in your component, Uniface will intelligently use the field’s declared syntax length to present the number cleanly to the user.

Conclusion

The Uniface float data type offers significant internal power and precision for your numerical computations. However, mastering its use means understanding not just its internal capabilities but also its interaction with your chosen database. By being mindful of database precision limitations, you can ensure your Uniface applications handle numerical data with accuracy and reliability.

Happy coding!