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Library/Backend/Java
Easy#java

NullPointerException (NPE) trong Java là gì và các cách phòng tránh hiệu quả?

February 15, 2026

Quick summary

NullPointerException (NPE) is a runtime exception that occurs when a program attempts to use an object reference that has a `null` value. To prevent it, developers should apply Yoda conditions, use `Optional`, perform fail-fast checks with `Objects.requireNonNull()`, or utilize static analysis annotations.

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