diff --git a/src/org/eidecker/oca8lernen/general/ArrayFun.java b/src/org/eidecker/oca8lernen/general/ArrayFun.java
new file mode 100644
index 0000000..eab3124
--- /dev/null
+++ b/src/org/eidecker/oca8lernen/general/ArrayFun.java
@@ -0,0 +1,35 @@
+package org.eidecker.oca8lernen.general;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author seidecke.
+ */
+public class ArrayFun {
+
+	char index;
+
+	@Test
+	public void testArrayInit() {
+		String[] strings = {"Hallo", "Welt"};
+		assertEquals(0, index);
+		assertEquals("Hallo", strings[index]);
+
+		assertEquals("Hallo", strings[(byte) 1]);
+		assertEquals("Hallo", strings[(short) 1]);
+		assertEquals("Hallo", strings[(char) 1]);
+
+		// assertEquals("Hallo", strings[(float) 1]); // Compilerfehler, muss Ganzzahl sein
+		// assertEquals("Hallo", strings[(long) 1]); // Compilerfehler, muss int oder kleiner sein
+
+		// Arrayklammern vor und nach Variablenname erlaubt
+		String [] twodim [];
+
+		String[][] twoDimStrings = {strings};
+
+
+	}
+
+}
diff --git a/src/org/eidecker/oca8lernen/general/ForEach.java b/src/org/eidecker/oca8lernen/general/ForEach.java
new file mode 100644
index 0000000..bf71626
--- /dev/null
+++ b/src/org/eidecker/oca8lernen/general/ForEach.java
@@ -0,0 +1,24 @@
+package org.eidecker.oca8lernen.general;
+
+import java.util.List;
+import org.junit.jupiter.api.Test;
+
+/**
+ * @author seidecke.
+ */
+public class ForEach {
+
+	@Test
+	public void testLaufvariable() {
+
+		int[] ints = new int[5];
+
+		for (int i: ints)
+			System.out.println(i);
+
+
+		List<String> sList;
+
+
+	}
+}
diff --git a/src/org/eidecker/oca8lernen/general/PrimitiveUndWrapperTest.java b/src/org/eidecker/oca8lernen/general/PrimitiveUndWrapperTest.java
index 2a1c4cb..bd873c2 100644
--- a/src/org/eidecker/oca8lernen/general/PrimitiveUndWrapperTest.java
+++ b/src/org/eidecker/oca8lernen/general/PrimitiveUndWrapperTest.java
@@ -37,6 +37,13 @@ public class PrimitiveUndWrapperTest {
 //		System.out.println(s);
 	}
 
+	@Test
+	public void literalUnderscore() {
+		// int i = 1_1_;
+
+		double d = 1_1.1_1;
+	}
+
 	@Test
 	public void wrapperEquals() {
 
diff --git a/src/org/eidecker/oca8lernen/general/StringIndex.java b/src/org/eidecker/oca8lernen/general/StringIndex.java
index 9a22e63..d8c2180 100644
--- a/src/org/eidecker/oca8lernen/general/StringIndex.java
+++ b/src/org/eidecker/oca8lernen/general/StringIndex.java
@@ -57,6 +57,12 @@ public class StringIndex {
 
 		testStringBuilder = new StringBuilder("1234567890");
 		assertEquals("12345890", testStringBuilder.delete(5,7).toString());
+
+
+		testStringBuilder = new StringBuilder("1234567890");
+		assertEquals("1234567890", testStringBuilder.delete(5,5).toString());
+
+
 		testStringBuilder = new StringBuilder("1234567890");
 		assertEquals("71234567890", testStringBuilder.insert(0,7).toString());
 		testStringBuilder = new StringBuilder("1234567890");
diff --git a/src/org/eidecker/oca8lernen/general/SwitchSyntax.java b/src/org/eidecker/oca8lernen/general/SwitchSyntax.java
index c64e3e0..87fd1ac 100644
--- a/src/org/eidecker/oca8lernen/general/SwitchSyntax.java
+++ b/src/org/eidecker/oca8lernen/general/SwitchSyntax.java
@@ -23,6 +23,24 @@ public class SwitchSyntax {
 	}
 	// Todo SeEi
 
+	@Test
+	public void switchWithComputation() {
+
+		final int i = 3;
+
+		switch(getSwitchBEdingung()) {
+			case i:
+				System.out.println("i");
+				break;
+			case i-1:
+				System.out.println("i-1");
+			default:
+				System.out.println("Was anderes");
+		}
+
+
+	}
+
 	@Test
 	public void switchString() {
 		switch (getString()) {