Operators

- I am correct in decoding the bitwise operations, added information about it

Basics/operators/Operators/.gitignore

@@ -0,0 +1 @@
+/target/

Basics/operators/Operators/pom.xml

@@ -0,0 +1,81 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <modelVersion>4.0.0</modelVersion>
+
+  <groupId>ocp.practice.basics</groupId>
+  <artifactId>Operators</artifactId>
+  <version>0.0.1-SNAPSHOT</version>
+
+  <name>Operators</name>
+  <description>A simple Operators.</description>
+  <!-- FIXME change it to the project's website -->
+  <url>http://www.example.com</url>
+
+  <properties>
+    <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
+    <maven.compiler.source>1.7</maven.compiler.source>
+    <maven.compiler.target>1.7</maven.compiler.target>
+  </properties>
+
+  <dependencies>
+    <dependency>
+      <groupId>junit</groupId>
+      <artifactId>junit</artifactId>
+      <version>3.8.1</version>
+    </dependency>
+  </dependencies>
+
+  <build>
+    <pluginManagement><!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) -->
+      <plugins>
+        <plugin>
+          <artifactId>maven-clean-plugin</artifactId>
+          <version>3.1.0</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-site-plugin</artifactId>
+          <version>3.7.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-project-info-reports-plugin</artifactId>
+          <version>3.0.0</version>
+        </plugin>
+        <!-- see http://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging -->
+        <plugin>
+          <artifactId>maven-resources-plugin</artifactId>
+          <version>3.0.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-compiler-plugin</artifactId>
+          <version>3.8.0</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-surefire-plugin</artifactId>
+          <version>2.22.1</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-jar-plugin</artifactId>
+          <version>3.0.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-install-plugin</artifactId>
+          <version>2.5.2</version>
+        </plugin>
+        <plugin>
+          <artifactId>maven-deploy-plugin</artifactId>
+          <version>2.8.2</version>
+        </plugin>
+      </plugins>
+    </pluginManagement>
+  </build>
+
+  <reporting>
+    <plugins>
+      <plugin>
+        <artifactId>maven-project-info-reports-plugin</artifactId>
+      </plugin>
+    </plugins>
+  </reporting>
+</project>

Basics/operators/Operators/src/main/java/ocp/practice/basics/Operators/App.java

@@ -0,0 +1,57 @@
+package ocp.practice.basics.Operators;
+
+/**
+ * Practicing operators
+ *
+ */
+public class App 
+{
+    public static void main(String[] args)
+    {
+    	/**
+    	 * Practice post and pre-increment
+    	 */
+//    	postIncrementAndPreIncrement();
+    	
+    	/**
+    	 * Practice the stuff below
+    	 */
+    	int a = 2; //...00010]
+    	int b = ~0; // 1...11]
+    	int c = a^b;// 1..101] // Pretty big (and negative, I'd say -3)
+    	System.out.println(c);
+    }
+    
+    public static void postIncrementAndPreIncrement()
+    {
+    	int i = 0;
+        
+        /**
+         * This is the POST-INCREMENT
+         * meaning the integer is
+         * increased but the value
+         * returned is PRIOR to
+         * incrementation
+         * 
+         * i++
+         */
+        System.out.println(i++); // 0
+        
+        /**
+         * This is the PRE-INCREMENT
+         * meaning the integer is increased
+         * but the value returned is,
+         * is AFTER the incrementation
+         * 
+         * ++i
+         */
+        System.out.println(++i); // 2
+        
+        /**
+         * Remember it like this:
+         * 
+         * i (then) ++     In other words, give me i, THEN increment it
+         * ++ (then) i	   In other words, increment i, THEN give me it
+         */
+    }
+}

Basics/operators/Operators/src/site/site.xml

@@ -0,0 +1,26 @@
+<?xml version="1.0" encoding="UTF-8"?>
+
+<project name="Operators" xmlns="http://maven.apache.org/DECORATION/1.8.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/DECORATION/1.8.0 http://maven.apache.org/xsd/decoration-1.8.0.xsd">
+  <bannerLeft>
+    <name>Operators</name>
+    <src>https://maven.apache.org/images/apache-maven-project.png</src>
+    <href>https://www.apache.org/</href>
+  </bannerLeft>
+
+  <bannerRight>
+    <src>https://maven.apache.org/images/maven-logo-black-on-white.png</src>
+    <href>https://maven.apache.org/</href>
+  </bannerRight>
+
+  <skin>
+    <groupId>org.apache.maven.skins</groupId>
+    <artifactId>maven-fluido-skin</artifactId>
+    <version>1.7</version>
+  </skin>
+
+  <body>
+    <menu ref="parent" />
+    <menu ref="reports" />
+  </body>
+</project>

Basics/operators/Operators/src/test/java/ocp/practice/basics/Operators/AppTest.java

@@ -0,0 +1,38 @@
+package ocp.practice.basics.Operators;
+
+import junit.framework.Test;
+import junit.framework.TestCase;
+import junit.framework.TestSuite;
+
+/**
+ * Unit test for simple App.
+ */
+public class AppTest 
+    extends TestCase
+{
+    /**
+     * Create the test case
+     *
+     * @param testName name of the test case
+     */
+    public AppTest( String testName )
+    {
+        super( testName );
+    }
+
+    /**
+     * @return the suite of tests being tested
+     */
+    public static Test suite()
+    {
+        return new TestSuite( AppTest.class );
+    }
+
+    /**
+     * Rigourous Test :-)
+     */
+    public void testApp()
+    {
+        assertTrue( true );
+    }
+}

IO/IO/src/main/java/ocp/io/IO/App.java

@@ -6,6 +6,7 @@ import java.io.IOException;
 import java.io.OutputStream;
 import java.io.PrintWriter;
 import java.io.StringReader;
+import java.util.Arrays;
 import java.io.FileInputStream;
 import java.io.InputStream;
 import java.io.InputStreamReader;
@@ -91,5 +92,47 @@ public class App
          * Close it
          */
         reader.close();
+        
+        /**
+         * The below is to revise a question that was asked in the
+         * Java OCP exam (round 1)
+         * 
+         * It was a loop that read into an array, a request of 8
+         * bytes each time and prints out the final array or 
+         * something akin to that. It also loop whilst
+         * the read call did not yet reach the end of file.
+         * 
+         * Given a file in `text.txt` containing solely
+         * `0123456789` (10 bytes), this should do one
+         * read, then another and then stop
+         */
+        File testFile = new File("text.txt");
+        FileInputStream fileStream = new FileInputStream(testFile);
+        reader = new BufferedReader(new InputStreamReader(fileStream));
+        
+        /**
+         * I believe they'd then print the string
+         * of this array of characters each loop
+         * 
+         * The below would print:
+         * 
+         * 01234567 (followed by) 8901234567
+         * 
+         * So it would print out: 012345678901234567 
+         */
+        char[] dataOut = new char[8];
+        while(reader.read(dataOut) != -1)
+        {
+        	System.out.print(new String(dataOut));
+        }
+        
+        // Final data will be `89234567`
+        System.out.println("\nFinal data: "+Arrays.toString(dataOut));
+        
+        /**
+         * Close it all
+         */
+        reader.close();
+        fileStream.close();
     }
 }

IO/IO/text.txt

@@ -0,0 +1 @@
+0123456789

OOP/oop/oop/src/main/java/ocp/OOP/oop/EnumTests.java

@@ -1,5 +1,7 @@
 package ocp.OOP.oop;
 
+import java.util.Arrays;
+
 /**
  * Playing around with enums
  * 
@@ -52,6 +54,8 @@ public class EnumTests
 	 */
 	public static void go()
 	{
+		System.out.println("\n\n<<< begin enum tests >>>\n\n");
+		
 		/**
 		 * An enum is a class-type hence every
 		 * instance if a reference and the constants
@@ -74,5 +78,11 @@ public class EnumTests
 		System.out.println(b1 == b3); //false
 		System.out.println(b1);
 		
+		
+		BodyType[] values = BodyType.values();
+		System.out.println("BodyType values: "+Arrays.toString(values));
+		System.out.println("Value of: "+BodyType.valueOf("SLIM") +(BodyType.valueOf("SLIM") == BodyType.SLIM));
+		
+		System.out.println("\n\n<<< end enum tests >>>\n\n");
 	}
 }

OOP/oop/oop/src/main/java/ocp/OOP/oop/SchoolGrade.java

@@ -25,6 +25,9 @@ package ocp.OOP.oop;
 public record SchoolGrade(Person person, int finalMark)
 {
 	
+	// The below is NOT allowed
+//	int j = 100;
+	
 	record Thing(int i)
 	{
 		
@@ -63,7 +66,7 @@ public record SchoolGrade(Person person, int finalMark)
 //		{
 //			person = null;
 //		}
-		
+//		
 //		finalMark = 69;
 		
 		/**
@@ -71,6 +74,9 @@ public record SchoolGrade(Person person, int finalMark)
 		 * 
 		 * this.person = person;
 		 * this.finalMark = finalMark;
+		 * 
+		 * NOTE: You CANNOT specify it
+		 * yourself if you do this!
 		 */
 	}
 }