diff --git a/src/org/eidecker/oca8lernen/general/Calcs.java b/src/org/eidecker/oca8lernen/general/Calcs.java
new file mode 100644
index 0000000..414f9ac
--- /dev/null
+++ b/src/org/eidecker/oca8lernen/general/Calcs.java
@@ -0,0 +1,18 @@
+package org.eidecker.oca8lernen.general;
+
+import org.w3c.dom.ls.LSOutput;
+
+public class Calcs {
+
+	int root;
+	Calcs(int root) {
+		this.root = root++;
+	}
+
+	public static void main(String[] args) {
+		Calcs c = new Calcs(42);
+
+		System.out.println(++c.root);
+	}
+
+}
diff --git a/src/org/eidecker/oca8lernen/general/StaticNull.java b/src/org/eidecker/oca8lernen/general/StaticNull.java
new file mode 100644
index 0000000..167a44a
--- /dev/null
+++ b/src/org/eidecker/oca8lernen/general/StaticNull.java
@@ -0,0 +1,25 @@
+package org.eidecker.oca8lernen.general;
+
+class StaticNull {
+
+	private static String hello = "Hello Static";
+
+	public static final void main(String [] args) {
+		System.out.println("Hello");
+		StaticNull nullReference = getNull();
+		System.out.println(nullReference.hello);
+	}
+
+	private static StaticNull getNull() {
+
+		Long l = 828282L;
+		double d = 2.1;
+		float f = 2.1f;
+
+		float f2 = 0b11;
+		Long l2 = 0b111L;
+
+		return null;
+	}
+
+}
diff --git a/src/org/eidecker/oca8lernen/general/StringEquals.java b/src/org/eidecker/oca8lernen/general/StringEquals.java
new file mode 100644
index 0000000..69af56a
--- /dev/null
+++ b/src/org/eidecker/oca8lernen/general/StringEquals.java
@@ -0,0 +1,28 @@
+package org.eidecker.oca8lernen.general;
+
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertFalse;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+public class StringEquals {
+
+	@Test
+	public void testStringEquals() {
+
+		String s1 = "Hallo";
+		String s2 = "Hallo";
+
+		assertTrue(s1 == s2);
+
+		String s3 = new String("Hallo");
+		String s4 = new String("Hallo");
+
+		assertFalse(s3 == s4);
+
+		assertFalse(s1 == s3);
+	}
+
+
+}