Code reviewMediumcr-g301

Subject Regex recompileLevel Mid–Senior~18 minCommon in Code quality & review interviewsIndustries Software development

Question

Review this Java method that masks card-like numbers in each log line. It runs on millions of lines per export.

What a strong answer looks like

Separate real bugs from style. Rank issues by severity, point at the root cause rather than the symptom, and suggest a concrete fix — specific and kind.

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Code to reviewjava

1String maskLine(String line) {2    Pattern p = Pattern.compile("\\b\\d{13,16}\\b");3    return p.matcher(line).replaceAll("[REDACTED]");4}

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