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alvisespano · Jan 12, 2025 · a0b9877 · a0b9877
1 parent ddf19f2
commit a0b9877
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Showing 3 changed files with 67 additions and 3 deletions.
diff --git a/2024-25/LezioniJava24-25/src/misc/Functional.java b/2024-25/LezioniJava24-25/src/misc/Functional.java
@@ -7,6 +7,8 @@
 
 public class Functional {
 
+
+
     public interface Function<A, B> {
         B apply(A x);
     }
@@ -102,12 +104,13 @@ public Integer apply(String x) {
 
         {
             List<Integer> l = List.of(-56, 345, 11, 0, -456, 23);
+            final int k = 0;
             Collection<Boolean> r = map(l, new Function<Integer, Boolean>() {
                 public Boolean apply(Integer x) {
-                    return x > 0;
+                    return x > k;
                 }
             });
-            Collection<Boolean> r2 = map(l, (x) -> x > 0);
+            Collection<Boolean> r2 = map(l, (x) -> x > k);
         }
 
         {

diff --git a/2024-25/LezioniJava24-25/src/misc/Sorting.java b/2024-25/LezioniJava24-25/src/misc/Sorting.java
@@ -0,0 +1,47 @@
+package misc;
+
+import java.util.ArrayList;
+import java.util.Collections;
+import java.util.Comparator;
+import java.util.List;
+
+public class Sorting {
+
+
+    public static <T extends Comparable<? super T>> void sort(List<T> list) { ... }
+
+
+    /*public interface Comparator<T> {
+        int compare(T o1, T o2);
+    }*/
+
+    public static void main(String[] args) {
+        {
+            List<Zoo.Dog> l = new ArrayList<>();
+            l.add(new Zoo.Dog(20, "mio"));
+            l.add(new Zoo.Dog(29, "mio"));
+            l.add(new Zoo.Dog(28, "mio"));
+            sort(l);
+
+
+
+
+            Collections.sort(l, new Comparator<>() {
+                @Override
+                public int compare(Zoo.Animal a, Zoo.Animal b) {
+                    return a.weight - b.weight;
+                }
+            });
+        }
+        {
+            List<String> l = List.of("ciao", "pippo", "gigio", "byebye");
+            Collections.sort(l, new Comparator<>() {
+                public int compare(String a, String b) {
+                    return b.length() - a.length();
+                }
+            });
+        }
+    }
+
+
+}
diff --git a/2024-25/LezioniJava24-25/src/misc/Zoo.java b/2024-25/LezioniJava24-25/src/misc/Zoo.java
@@ -2,7 +2,7 @@
 
 public class Zoo {
 
-    public static class Animal {
+    public static class Animal implements Comparable<Animal> {
 
         protected int weight;
 
@@ -13,6 +13,11 @@ public Animal(int weight) {
         public void eat(Animal a) {
             this.weight += a.weight;
         }
+
+        @Override
+        public int compareTo(Animal o) {
+            return this.weight - o.weight;
+        }
     }
 
     public static class Dog extends Animal {
@@ -23,6 +28,15 @@ public Dog(int weight, String owner) {
             this.owner = owner;
         }
 
+        @Override
+        public int compareTo(Animal o) {
+            if (o instanceof Dog) {
+                Dog d = (Dog) o;
+                ...
+            }
+            else return super.compareTo(o);
+        }
+
         public void bark() {
             System.out.println("BAUUU!");
         }