misc chapter 13 stuff, breaks, exceptions and loops

Author: tobyweston

src/main/java/s4j/java/chapter13/Breaks.java

@@ -0,0 +1,11 @@
+package s4j.java.chapter13;
+
+public class Breaks {
+    public static void main(String... args) {
+        for (int i = 0; i < 100; i++) {
+            System.out.println(i);
+            if (i == 10)
+                break;
+        }
+    }
+}

src/main/java/s4j/java/chapter13/Exceptions.java

@@ -0,0 +1,28 @@
+package s4j.java.chapter13;
+
+import java.io.BufferedReader;
+import java.io.IOException;
+import java.io.InputStreamReader;
+import java.net.MalformedURLException;
+import java.net.URL;
+
+public class Exceptions {
+
+    public static void main(String... args) {
+        try {
+            URL url = new URL("http://baddotrobot.com");
+            BufferedReader reader = new BufferedReader(new InputStreamReader(url.openStream()));
+            try {
+                String line;
+                while ((line = reader.readLine()) != null)
+                    System.out.println(line);
+            } finally {
+                reader.close();
+            }
+        } catch (MalformedURLException e) {
+            System.out.println("Bad URL");
+        } catch (IOException e) {
+            System.out.println("Problem reading data from the web: " + e.getMessage());
+        }
+    }
+}

src/main/java/s4j/java/chapter13/Loops.java

@@ -0,0 +1,48 @@
+package s4j.java.chapter13;
+
+import java.util.Arrays;
+import java.util.List;
+
+public class Loops {
+
+    public static class Do {
+        public static void main(String... args) {
+            int i = 0;
+            do {
+                System.out.println(i);
+                i++;
+            } while (i < 10);
+        }
+    }
+
+    public static class While {
+        public static void main(String... args) {
+            int i = 0;
+            while (i < 10) {
+                System.out.println(i);
+                i++;
+            }
+        }
+    }
+
+    public static class For {
+        public static void main(String... args) {
+            for (int i = 0; i < 10; i++) {
+                System.out.println(i);
+            }
+        }
+    }
+
+    public static class EnhancedFor {
+        public static void main(String... args) {
+            List<Integer> numbers = Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10);
+            for (Integer i : numbers) {
+                System.out.println(i);
+            }
+
+            numbers.forEach(i -> System.out.println(i));
+            numbers.forEach(System.out::println);
+        }
+    }
+
+}

src/main/scala/s4j/scala/chapter13/Breaks.scala

@@ -0,0 +1,26 @@
+package s4j.scala.chapter13
+
+import scala.util.control.Breaks._
+
+object Breaks extends App {
+  var i: Int = 0
+  breakable {
+    while (i < 100) {
+      System.out.println(i)
+      if (i == 10)
+        break()
+      i += 1
+    }
+  }
+
+  breakable {
+    for (i <- 0 to 100) {
+      System.out.println(i)
+      if (i == 10)
+        break()
+    }
+  }
+}
+
+
+

src/main/scala/s4j/scala/chapter13/Exceptions.scala

@@ -0,0 +1,78 @@
+
+package s4j.scala.chapter13
+
+import java.io._
+import java.net.{MalformedURLException, URL}
+
+
+object Exceptions extends App {
+
+  autocloseExample()
+
+  def example2() = try {
+    val url = new URL("http://baddotrobot.com")
+    val reader = new BufferedReader(new InputStreamReader(url.openStream))
+    try {
+      var line = reader.readLine
+      while (line != null) {
+        line = reader.readLine
+        println(line)
+      }
+    } finally {
+      reader.close()
+    }
+  } catch {
+    case _: MalformedURLException => System.out.println("Bad URL")
+    case e: IOException => System.out.println("Problem reading data from the web: " + e.getMessage)
+  }
+
+  def autoclose[A, B <: Closeable](resource: B)(f: => A): A =
+    try {
+      f
+    } finally {
+      resource.close()
+    }
+
+  def autocloseExample() = {
+    try {
+      val url = new URL("http://baddotrobot.com")
+      val reader = new BufferedReader(new InputStreamReader(url.openStream))
+      autoclose(reader) {
+        var line = reader.readLine
+        while (line != null) {
+          line = reader.readLine
+          println(line)
+        }
+      }
+    } catch {
+      case _: MalformedURLException => System.out.println("Bad URL")
+      case e: IOException => System.out.println("Problem reading data from the web: " + e.getMessage)
+    }
+  }
+
+  def try_[A, B <: Closeable](resource: B)(f: B => A): A =
+    try {
+      f(resource)
+    } finally {
+      resource.close()
+    }
+
+  def autocloseExample2() = {
+    try {
+      val url = new URL("http://baddotrobot.com")
+      try_(new BufferedReader(new InputStreamReader(url.openStream))) {
+        reader => {
+          var line = reader.readLine
+          while (line != null) {
+            line = reader.readLine
+            println(line)
+          }
+        }
+      }
+    } catch {
+      case _: MalformedURLException => System.out.println("Bad URL")
+      case e: IOException => System.out.println("Problem reading data from the web: " + e.getMessage)
+    }
+  }
+
+}

src/main/scala/s4j/scala/chapter13/Loops.scala

@@ -0,0 +1,51 @@
+
+package s4j.scala.chapter13
+
+object Do extends App {
+  var i = 0
+  do {
+    println(i)
+    i += 1
+  } while (i < 10)
+}
+
+object DoWithFor extends App {
+  var i = 0
+  do {
+    for (j <- 0 to i)
+      print("*")
+    print("\n")
+    i += 1
+  } while (i < 10)
+}
+
+object While extends App {
+  var i = 0
+  while (i < 10) {
+    println(i)
+    i += 1
+  }
+}
+
+object ForAsAWhile extends App {
+  var i = 0
+  while (i < 10) {
+    println(i)
+    i += 1
+  }
+}
+
+object For extends App {
+  for (i <- 0 to 10) {
+    println(i)
+  }
+
+  (0 to 10).foreach(i => println(i))
+  (0 to 10).foreach(println(_))
+
+}
+
+
+
+
+

src/main/scala/s4j/scala/chapter13/Ternary.scala

@@ -1,7 +1,10 @@
+
 package s4j.scala.chapter13
 
 object Ternary {
-  val height = 90
 
+  val height = 90
   val tall = if (height > 190) "tall" else "not tall"
+
+  println(tall)
 }