Varargs in Java: Variable-Argument Methods

Varargs in Java: Variable-Argument Methods

Varargs (...) lets a method accept zero or more arguments of the same type.

Real-World Use Cases

• utility logging methods
• SQL/criteria builders
• event publishing with optional metadata

Java 8 Example

public static int sum(int... values) {
    int total = 0;
    for (int value : values) {
        total += value;
    }
    return total;
}

Java 21+ Example

public static String joinWithPrefix(String prefix, String... parts) {
    return prefix + String.join(",", parts);
}

Varargs behavior is unchanged across Java 8, JDK 11, Java 17, Java 21, and Java 25. Improvements in newer versions are around surrounding language features, not varargs itself.

Rules

• only one varargs parameter allowed
• varargs must be last parameter
• internally treated as array

Key Takeaways

• Varargs improves API ergonomics for optional lists of inputs.
• Avoid ambiguous overloads with boxed/primitive varargs combinations.
• Prefer explicit overloads when readability is more important than flexibility.