The use of punctuation characters to separate subgroups in a number can make the number more readable. For instance consider 1,000,000,000 versus 1000000000. But when the grouping is irregular, such as 1,000,00,000; it indicates an error.

This rule raises an issue when underscores (_) are used to break a number into irregular subgroups.

Noncompliant Code Example

int duos = 1_00_00;
int million = 1_000_00_000;  // Noncompliant
int thousand = 1000;
int tenThousand = 100_00;  // Noncompliant