Unpredictable 'BigDecimal' constructor call

Reports calls to BigDecimal constructors that accept a double value. These constructors produce BigDecimal that is exactly equal to the supplied double value. However, because doubles are encoded in the IEEE 754 64-bit double-precision binary floating-point format, the exact value can be unexpected.

For example, new BigDecimal(0.1) yields a BigDecimal object. Its value is 0.1000000000000000055511151231257827021181583404541015625 which is the nearest number to 0.1 representable as a double. To get BigDecimal that stores the same value as written in the source code, use either new BigDecimal("0.1") or BigDecimal.valueOf(0.1).

Example:

  class Constructor {
    void foo() {
      new BigDecimal(0.1);
    }
  }

After the quick-fix is applied:

  class Constructor {
    void foo() {
      new BigDecimal("0.1");
    }
  }

Locating this inspection

By ID

Can be used to locate inspection in e.g. Qodana configuration files, where you can quickly enable or disable it, or adjust its settings.

UnpredictableBigDecimalConstructorCall

Via Settings dialog

Path to the inspection settings via IntelliJ Platform IDE Settings dialog, when you need to adjust inspection settings directly from your IDE.

Settings or Preferences | Editor | Inspections | Java | Numeric issues

Inspection options

Here you can find the description of settings available for the Unpredictable 'BigDecimal' constructor call inspection, and the reference of their default values.

Ignore constructor calls with variable or method call arguments: Default: Selected
Ignore constructor calls with multiple literals (e.g. 0.1 + 0.2): Not selected

Inspection Details
By default bundled with:	IntelliJ IDEA 2024.2, Qodana for JVM 2024.2,
Can be installed with plugin:	Java, 242.22892

Last modified: 11 September 2024