Static

Static keyword means “belongs to the class, not to an instance”.
You can access static members without creating an object.

Static Usage Summary

Use With	Effect
Variable	Shared across all instances
Method	Can be called without an object
Block	Static initializer runs once when the class loads
Class (nested)	Declared a static nested class

Example

Static Variable

class Counter {
    static int count = 0;
    
    Counter() {
        count++;
    }
}
 
System.out.println(Counter.count);
// Value shared across all instances

Static Method

class MathUtil {
    static int square(int x) {
        return x * x;
    }
}
 
int result = MathUtil.square(5); // No object needed

Static Block

class InitExample {
    static { // Executes once when class is loaded
        System.out.println("Class loaded");
    }
}

Static-Nested Class

class Outer {
    static class Inner {
        void show() {
            System.out.println("Static Nested Class");
        }
    }
}
 
Outer.Inner obj = new Outer.Inner();
obj.show();

Tip

Mention static when asked about:

• utility classes (Math, Collections),
• shared variables,
• main() method: public static void main(…),
• why static methods can’t access instance members directly.

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Parent: _Core