This is a reference entry from MDN Web Docs. A full explanation with fixes has not been written yet.
SyntaxError: Unexpected reserved word (V8-based)
SyntaxError: implements is a reserved identifier (Firefox)
SyntaxError: Cannot use the reserved word 'implements' as a variable name. (Safari)
- Category
- SyntaxError
- Severity
- error
- Runtime
- both
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Source: MDN Web Docs. Data fetched 2026-09-25T01:48:37.274Z.