Lesson3: Heap and Stack

 Stack - more controllable memory area. LIFO prinsipi ile calishir. 

Heap - hard to control. Stack - dan balacadir.

package az.etibarli;

import java.util.Arrays;
import java.util.function.Predicate;

public class StackDemo {
    private static String[] methods = {"f", "g", "main", "u"};
    private static int uCallCount;

    public static void main(String[] args) {
        printStackTrace(1);
        f();
        printStackTrace(7);
        u();
        printStackTrace(9);
    }

    public static void f() {
        printStackTrace(2);
        int i = 5;
        String s1 = new String("Java!");
        g(false);
        printStackTrace(4);
        g(true);
        i++;
    }

    public static void g(boolean b) {
        if (!b)
            printStackTrace(3);
        else
            printStackTrace(5);
        int i = 5;
        i++;
        String s1 = new String("Java!");
        if (b)
            u();
    }

    public static void u() {
        if (uCallCount == 0) {
            printStackTrace(6);
            uCallCount++;
        } else
            printStackTrace(8);
        int i = 5;
        String s1 = new String("Java!");
    }

    public static void printStackTrace(int breakPoint) {
        System.out.println("=============================");
        System.out.println("Break Point " + breakPoint + " ||");
        Predicate<String> isInArray = s -> {
            int position = Arrays.binarySearch(methods, s);
            if (position >= 0)
                return true;
            else return false;
        };

        StackTraceElement[] stackTraceElements = Thread.currentThread().getStackTrace();
        for(StackTraceElement element : stackTraceElements) {
            String methodName = element.getMethodName();
            if(isInArray.test(methodName))
                System.out.printf("%-13s %-2s\n", methodName, "||");
        }
        System.out.println("==============================");
    }
}

                                                                            Scope

package az.etibarli;

public class ScopeDemo {
    int i = 1;

    public static void main(String[] args) {
        int i = 0;
        System.out.println(i);

        for (; i < 5; i++) {
            System.out.println(i);
            if (i < 3) {
                int ii = 3;
                int a;
                f(ii);
            } else if (3 < i & i < 12) {
                int ii = 8;
                f(ii);
            } else {
                int ii = 17;
                f(ii);
            }
        }
    }

    public static void f(int i) {
        System.out.println(i);
    }
}