Add complete chapter 4

DG-DanielDev · DG-DanielDev · commit d12e5eadcc20 · 2024-09-30T13:41:47.000-03:00
Signed-off-by: DanielDG &lt;danielramososielrodrigues@gmail.com&gt;
diff --git a/src/chapter4/exercises/becompiler/clock/Clock.java b/src/chapter4/exercises/becompiler/clock/Clock.java
@@ -0,0 +1,11 @@
+package chapter4.exercises.becompiler.clock;
+
+public class Clock {
+  String time;
+   void setTime(String t) {
+     time = t;
+   }
+   String getTime() {
+     return time;
+   }
+}
diff --git a/src/chapter4/exercises/becompiler/clock/ClockTestDrive.java b/src/chapter4/exercises/becompiler/clock/ClockTestDrive.java
@@ -0,0 +1,11 @@
+package chapter4.exercises.becompiler.clock;
+
+public class ClockTestDrive {
+  public static void main(String[] args) {
+    Clock c = new Clock();
+
+    c.setTime("1245");
+    String tod = c.getTime();
+    System.out.println("time: " + tod);
+  }
+}
diff --git a/src/chapter4/exercises/becompiler/xcopy/XCopy.java b/src/chapter4/exercises/becompiler/xcopy/XCopy.java
@@ -0,0 +1,14 @@
+package chapter4.exercises.becompiler.xcopy;
+
+public class XCopy {
+  public static void main(String[] args) {
+    int orig = 42;
+    XCopy x = new XCopy();
+    int y = x.go(orig);
+    System.out.println(orig + " " + y);
+  }
+  int go(int arg) {
+    arg = arg * 2;
+    return arg;
+  }
+}
diff --git a/src/chapter4/exercises/mixedmessages/Mix4.java b/src/chapter4/exercises/mixedmessages/Mix4.java
@@ -0,0 +1,26 @@
+package chapter4.exercises.mixedmessages;
+
+public class Mix4 {
+  int counter = 0;
+  public static void main(String[] args) {
+    int count = 0;
+    Mix4[] m4a = new Mix4[20];
+    int x = 0;
+    while(x<19) {
+      m4a[x] = new Mix4();
+      m4a[x].counter = m4a[x].counter + 1;
+      count = count + 1;
+      count = count + m4a[x].maybeNew(x);
+      x = x + 1;
+    }
+    System.out.println(count + " "  + m4a[1].counter);
+  }
+  public int maybeNew(int index) {
+    if(index < 1) {
+      Mix4 m4 = new Mix4();
+      m4.counter = m4.counter + 1;
+      return 1;
+    }
+    return 0;
+  }
+}
diff --git a/src/chapter4/exercises/poopuzzle/Puzzle4.java b/src/chapter4/exercises/poopuzzle/Puzzle4.java
@@ -0,0 +1,22 @@
+package chapter4.exercises.poopuzzle;
+
+public class Puzzle4 {
+  public static void main(String[] args) {
+    Puzzle4b[] obs = new Puzzle4b[6];
+    int y = 1;
+    int x = 0;
+    int result = 0;
+    while(x<6) {
+      obs[x] = new Puzzle4b();
+      obs[x].ivar = y;
+      y = y * 10;
+      x = x + 1;
+    }
+    x = 6;
+    while(x>0) {
+      x = x - 1;
+      result = result + obs[x].doStuff(x);
+    }
+    System.out.println("result " + result);
+  }
+}
diff --git a/src/chapter4/exercises/poopuzzle/Puzzle4b.java b/src/chapter4/exercises/poopuzzle/Puzzle4b.java
@@ -0,0 +1,12 @@
+package chapter4.exercises.poopuzzle;
+
+public class Puzzle4b {
+  int ivar;
+  public int doStuff(int factor){
+    if(ivar>100) {
+      return ivar*factor;
+    } else {
+      return ivar * (5-factor);
+    }
+  }
+}
