泛型类、泛型方法、泛型接口

src/chapter6/Example23.java

@@ -1,4 +1,29 @@
 package chapter6;
 
+
+import java.util.ArrayList;
+import java.util.Iterator;
+
+
 public class Example23 {
+    public static void main(String[] args) {
+        // 存放字符串的集合
+        ArrayList<String> names = new ArrayList<String>();
+        names.add("张三");  // √ 正确
+
+        Iterator it1 = names.iterator();
+        while (it1.hasNext()) {
+            String name = (String) it1.next();
+            System.out.println(name);
+        }
+
+        ArrayList students = new ArrayList();
+        names.add("张三");
+
+        Iterator it2 = students.iterator();
+        while (it2.hasNext()) {
+            String student = (String) it2.next();
+            System.out.println(student);
+        }
+    }
 }