Call to 'Number.toString()'

Reports toString() calls on objects of a class extending Number. Such calls are usually incorrect in an internationalized environment and some locale specific formatting should be used instead.

Example:

  void print(Double d) {
    System.out.println(d.toString());
  }

A possible way to fix this problem could be:

  void print(Double d) {
    System.out.printf("%f%n", d);
  }

This formats the number using the default locale which is set during the startup of the JVM and is based on the host environment.

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.

CallToNumericToString

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 | Internationalization

Suppressing Inspection

You can suppress this inspection by placing the following comment marker before the code fragment where you no longer want messages from this inspection to appear:

//noinspection CallToNumericToString

More detailed instructions as well as other ways and options that you have can be found in the product documentation:

IntelliJ IDEA 2025.2

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.2, Qodana for JVM 2025.2,

Last modified: 18 September 2025