Static methods in interfaces

Java 8 allows static methods in interfaces. They belong to the interface itself, not to implementing classes.

Syntax:

interface MathUtils {
    static int add(int a, int b) {
        return a + b;
    }
}

Usage:

int sum = MathUtils.add(5, 3);  // called on the interface, not on an instance

Important rules:

• Static methods cannot be overridden by implementing classes.
• They are not inherited by implementing classes (unlike default methods).
• They can only be accessed using the interface name.

class MyMath implements MathUtils {
    // Cannot override static add()
    void test() {
        // add(1,2); // error: cannot call static method from interface via class
        MathUtils.add(1,2); // correct
    }
}

Use cases:

• Utility methods related to the interface (e.g., factory methods, helper functions).
• Grouping related static methods without needing a separate utility class.

Note: Static methods in interfaces cannot be called from an instance of the implementing class.