- 使用 Iterator 遍历 HashMap EntrySet
- 使用 Iterator 遍历 HashMap KeySet
- 使用 For-each 循环迭代 HashMap
- 使用 Lambda 表达式遍历 HashMap
- 使用 Stream API 遍历 HashMap
public class IterateHashMapExample { public static void main(String[] args) { // 1. 使用 Iterator 遍历 HashMap EntrySet Map < Integer, String > coursesMap = new HashMap < Integer, String > (); coursesMap.put(1, "C"); coursesMap.put(2, "C++"); coursesMap.put(3, "Java"); coursesMap.put(4, "Spring Framework"); coursesMap.put(5, "Hibernate ORM framework"); Iterator < Entry < Integer, String >> iterator = coursesMap.entrySet().iterator(); while (iterator.hasNext()) { Entry < Integer, String > entry = iterator.next(); System.out.println(entry.getKey()); System.out.println(entry.getValue()); } } }2. 使用 Iterator 遍历 HashMap KeySet
public class IterateHashMapExample { public static void main(String[] args) { Map < Integer, String > coursesMap = new HashMap < Integer, String > (); coursesMap.put(1, "C"); coursesMap.put(2, "C++"); coursesMap.put(3, "Java"); coursesMap.put(4, "Spring Framework"); coursesMap.put(5, "Hibernate ORM framework"); // 2. 使用 Iterator 遍历 HashMap KeySet Iterator < Integer > iterator = coursesMap.keySet().iterator(); while (iterator.hasNext()) { Integer key = iterator.next(); System.out.println(key); System.out.println(coursesMap.get(key)); } } }3. 使用 For-each 循环遍历 HashMap
public class IterateHashMapExample { public static void main(String[] args) { Map < Integer, String > coursesMap = new HashMap < Integer, String > (); coursesMap.put(1, "C"); coursesMap.put(2, "C++"); coursesMap.put(3, "Java"); coursesMap.put(4, "Spring Framework"); coursesMap.put(5, "Hibernate ORM framework"); // 3. 使用 For-each 循环遍历 HashMap for (Map.Entry < Integer, String > entry: coursesMap.entrySet()) { System.out.println(entry.getKey()); System.out.println(entry.getValue()); } } }
4. 使用 Lambda 表达式遍历 HashMap
public class IterateHashMapExample { public static void main(String[] args) { Map < Integer, String > coursesMap = new HashMap < Integer, String > (); coursesMap.put(1, "C"); coursesMap.put(2, "C++"); coursesMap.put(3, "Java"); coursesMap.put(4, "Spring Framework"); coursesMap.put(5, "Hibernate ORM framework"); // 4. 使用 Lambda 表达式遍历 HashMap coursesMap.forEach((key, value) -> { System.out.println(key); System.out.println(value); }); } }5. 使用 Stream API 遍历 HashMap
public class IterateHashMapExample { public static void main(String[] args) { Map < Integer, String > coursesMap = new HashMap < Integer, String > (); coursesMap.put(1, "C"); coursesMap.put(2, "C++"); coursesMap.put(3, "Java"); coursesMap.put(4, "Spring Framework"); coursesMap.put(5, "Hibernate ORM framework"); // 5. 使用 Stream API 遍历 HashMap coursesMap.entrySet().stream().forEach((entry) - > { System.out.println(entry.getKey()); System.out.println(entry.getValue()); }); } }