40

Author: viktorvoltz

Containers/com/viktorvoltz/Exercise40.java

@@ -0,0 +1,66 @@
+package com.viktorvoltz;
+
+import java.util.*;
+
+class TwoStrings40 implements Comparable<TwoStrings40> {
+    private String first = "";
+    private String second = "";
+
+    public TwoStrings40(String s1, String s2) {
+        first = s1;
+        second = s2;
+    }
+
+    // Using only first String to compare:
+    public int compareTo(TwoStrings40 ts) {
+        return first.compareTo(ts.first);
+    }
+
+    // Optional inner class to use second String to compare:
+    public static class Comp2 implements Comparator<TwoStrings40> {
+        public int compare(TwoStrings40 ts1, TwoStrings40 ts2) {
+            return ts1.second.compareTo(ts2.second);
+        }
+    }
+
+    public String toString() {
+        return first + " & " + second;
+    }
+
+    static void printArray(TwoStrings40[] sa) {
+        System.out.print("(");
+        for (int i = 0; i < sa.length - 1; i++)
+            System.out.print(sa[i] + ", ");
+        System.out.println(sa[sa.length - 1] + ")");
+    }
+
+    public static void main(String[] args) {
+        RandomGenerator.String rgs = new RandomGenerator.String(4);
+        TwoStrings40[] array = new TwoStrings40[5];
+        List<TwoStrings40> list = new ArrayList<TwoStrings40>();
+        for (int i = 0; i < array.length; i++) {
+            String s1 = rgs.next();
+            String s2 = rgs.next();
+            array[i] = new TwoStrings40(s1, s2);
+            list.add(new TwoStrings40(s1, s2));
+        }
+        System.out.print("Array: ");
+        printArray(array);
+        System.out.println("List: " + list);
+        Arrays.sort(array);
+        Collections.sort(list, null);
+        System.out.println();
+        System.out.println("Sorted by first word:");
+        System.out.print("Array: ");
+        printArray(array);
+        System.out.println("List: " + list);
+        TwoStrings40.Comp2 comp = new TwoStrings40.Comp2();
+        Arrays.sort(array, comp);
+        Collections.sort(list, comp);
+        System.out.println();
+        System.out.println("Sorted by second word:");
+        System.out.print("Array: ");
+        printArray(array);
+        System.out.println("List: " + list);
+    }
+}