public static void main(String[] args) {
        int repeats = 40000000;
        long time;

        time = System.currentTimeMillis();
        long counterA = 0L;
        for (int i = 0; i < repeats; i++) {
            counterA = counterA + 4L;
        }
        System.out.println(counterA + " A: " + (System.currentTimeMillis() - time) + " ms");

        time = System.currentTimeMillis();
        Long counterB = 0L;
        for (int i = 0; i < repeats; i++) {
            counterB = counterB + 4L;
        }
        System.out.println(counterB + " B: " + (System.currentTimeMillis() - time) + " ms");
    }

160000000 A: 0 ms
160000000 B: 284 ms

     public static void main(String[] args) {
        int repeats = 40000000;
        long time;

        time = System.currentTimeMillis();
        long counterA = 0L;
        for (int i = 0; i < repeats; i++) {
            counterA = counterA + 4L;
        }
        System.out.println(counterA + " A: " + (System.currentTimeMillis() - time) + " ms");

        time = System.currentTimeMillis();
        Long counterB = Long.valueOf(0L);
        for (int i = 0; i < repeats; i++) {
            counterB = counterB + 4L;
        }
        System.out.println(counterB + " B: " + (System.currentTimeMillis() - time) + " ms");
    }

160000000 A: 0 ms
160000000 B: 237 ms

Long l = new Long(0L);

   @IntrinsicCandidate
    public static Long valueOf(long l) {
        final int offset = 128;
        if (l >= -128 && l <= 127) { // will cache
            return LongCache.cache[(int)l + offset];
        }
        return new Long(l);
    }

⚡️ @javapro_ir
💬@group_javapro

public enum Permission {
    READ(1 << 0),     // 0001
    WRITE(1 << 1),    // 0010
    EXECUTE(1 << 2),  // 0100
    DELETE(1 << 3);   // 1000

    public final int value;

    Permission(int value) {
        this.value = value;
    }
}

public class PermissionSet {
    private int flags = 0;

    public void enable(Permission p) {
        flags |= p.value;
    }

    public void disable(Permission p) {
        flags &= ~p.value;
    }

    public boolean isEnabled(Permission p) {
        return (flags & p.value) != 0;
    }

    public void toggle(Permission p) {
        flags ^= p.value;
    }

    public int getRawValue() {
        return flags;
    }
}

public class Main {
    public static void main(String[] args) {
        PermissionSet userPermissions = new PermissionSet();

        userPermissions.enable(Permission.READ);
        userPermissions.enable(Permission.WRITE);

        System.out.println("Is write permission enabled?" + userPermissions.isEnabled(Permission.WRITE));
        
        userPermissions.disable(Permission.WRITE);

        System.out.println("Is write permission enabled? " + userPermissions.isEnabled(Permission.WRITE));

        userPermissions.toggle(Permission.EXECUTE);
        System.out.println("Is execution permission enabled? " + userPermissions.isEnabled(Permission.EXECUTE));
    }
}

Is write permission enabled? true  
Is write permission enabled? false  
Is execution permission enabled? true

#کاربرـحرفهـای

🆔 @javapro_ir
🆔 @group_javapro

#کاربر_مبتدی

🆔 @javapro_ir
🆔 @group_javapro