Using 'Random.nextDouble()' to get random integer

Reports calls to java.util.Random.nextDouble() that are used to create a positive integer number by multiplying the call by a factor and casting to an integer.

For generating a random positive integer in a range, java.util.Random.nextInt(int) is simpler and more efficient.

Example:

  int getRandomInt() {
    return (int) ((new Random()).nextDouble() * SIZE);
  }
  

After the quick-fix is applied:

  int getRandomInt() {
    return (new Random()).nextInt(SIZE);
  }

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.

UsingRandomNextDoubleForRandomInteger

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 | Performance

Inspection ID: RandomDoubleForRandomInteger

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 UsingRandomNextDoubleForRandomInteger

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

IntelliJ IDEA 2025.3

Inspection Details
By default bundled with:	IntelliJ IDEA 2025.3, Qodana for JVM 2025.3,

Last modified: 03 December 2025