11.10 Map

src/arrays/ContainerComparison.java

@@ -0,0 +1,47 @@
+package arrays;//: arrays/ContainerComparison.java
+import java.util.*;
+import static net.mindview.util.Print.*;
+
+class BerylliumSphere {
+  private static long counter;
+  private final long id = counter++;
+  public String toString() { return "Sphere " + id; }
+}
+
+public class ContainerComparison {
+  public static void main(String[] args) {
+    BerylliumSphere[] spheres = new BerylliumSphere[10];
+    for(int i = 0; i < 5; i++) {
+        spheres[i] = new BerylliumSphere();
+    }
+    print(Arrays.toString(spheres));
+    print(spheres[4]);
+
+    List<BerylliumSphere> sphereList =
+      new ArrayList<BerylliumSphere>();
+    for(int i = 0; i < 5; i++) {
+        sphereList.add(new BerylliumSphere());
+    }
+    print(sphereList);
+    print(sphereList.get(4));
+
+    int[] integers = { 0, 1, 2, 3, 4, 5 };
+    print(Arrays.toString(integers));
+    print(integers[4]);
+
+    List<Integer> intList = new ArrayList<Integer>(
+      Arrays.asList(0, 1, 2, 3, 4, 5));
+    intList.add(97);
+    print(intList);
+    print(intList.get(4));
+  }
+} /* Output:
+[Sphere 0, Sphere 1, Sphere 2, Sphere 3, Sphere 4, null, null, null, null, null]
+Sphere 4
+[Sphere 5, Sphere 6, Sphere 7, Sphere 8, Sphere 9]
+Sphere 9
+[0, 1, 2, 3, 4, 5]
+4
+[0, 1, 2, 3, 4, 5, 97]
+4
+*///:~