9. Decide whether your project allows negative values
Build this example in your Unreal project and compare the result at each step.
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The numeric policy determines which values the project accepts. It is independent of formatting: showing two decimal places does not change the stored value. Idle Mode is a global option; it is not a formatter setting or a property of a particular number.
- Note the current state of Idle Mode Enabled so you can restore it when finished. Stop Play and open Edit → Project Settings → Scientific Number Settings → Behavior.
- Turn off Idle Mode Enabled, save the configuration, and restart the editor.
- In BP_MiNumero, test Make Scientific Number with Base -2, 0.25, and 0, each with Exponent 0. Check each result with Is Success and Branch; use Get Error → Print Scientific Number Error for the failure.
- Stop Play, turn on Idle Mode Enabled, save, and restart the editor. Repeat exactly the same inputs.
| Input | Idle Mode disabled | Idle Mode enabled |
|---|---|---|
| -2 | Valid | Invalid Input |
| 0.25 | Valid | Valid |
| 0 | Valid | Valid |
- Restore the configuration you noted and restart before continuing with the other exercises.
What this means: Idle Mode rejects negative values. Zero and positive fractions such as 0.25 remain valid. A negative exponent represents a fraction, not a negative number. Idle Mode is disabled by default; enable it only if all your Scientific Numbers must be nonnegative. Whole-unit restrictions belong to your game rules.
When finished: choose the policy based on the values your game needs. Enabling Idle Mode does not turn numbers into integers or change their format.