Underscore used as identifier — CodeQL query help documentation

ID: java/underscore-identifier
Kind: problem
Security severity: 
Severity: recommendation
Precision: high
Tags:
   - quality
   - maintainability
   - readability
Query suites:
   - java-code-quality.qls
   - java-security-and-quality.qls

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The underscore character is a reserved keyword in Java 9 and therefore disallowed as a one-character identifier.

Recommendation¶

Rename any identifiers that consist of a one-character underscore.

References¶

Oracle JDK Documentation: Oracle JDK 9 Migration Guide.
JDK Bug System: Disallow _ as a one-character identifier.