問題是如何使用方法列印 HashMap 中 value = 1 的書籍printWhiteRavens(ArrayList<String> whiteRavens)？在代碼中，我洗掉了帶有書籍的陣列，因此代碼可以更短。
public static HashMap<String, Integer> createBooksCounter() {
HashMap<String,Integer> createBooksCounter = new HashMap<>();
createBooksCounter.put("Chicken Abroad",5);
createBooksCounter.put("Lord With Sins",3);
createBooksCounter.put("Fish And Horses",4);
createBooksCounter.put("Mistress Of Devotion",2);
createBooksCounter.put("Guardians And Gangsters",3);
createBooksCounter.put("Bandit Of The Void",1);
createBooksCounter.put("Lions Of Dread",1);
createBooksCounter.put("Future Of Fire",2);
createBooksCounter.put("Driving Into The Depths",1);
createBooksCounter.put("Starting The Demons",1);
createBooksCounter.put("Maid With Blue Eyes",2);
createBooksCounter.put("Lovers In The Forest",1);
createBooksCounter.put("Destruction Of The Faceless Ones",1);
return null;
}
public static void countBook(HashMap<String, Integer> booksCounter, String book) {
}
public static ArrayList<String> findWhiteRavens(HashMap<String, Integer> booksCounter) {
return null;
}
public static void printWhiteRavens(ArrayList<String> whiteRavens) {
return null;
}
public static void main(String[] args) {
}
uj5u.com熱心網友回復：
使用流：
yourMap.entrySet().stream().filter(e -> e.getValue() == 1)
.forEach(element -> System.out.println(element.getKey()));
uj5u.com熱心網友回復：
過濾地圖的所有條目，根據地圖的鍵創建一個串列，這些就是您的書名。傳遞該串列printWhiteRavens，然后列印標題：
public static void main(String[] args) {
Map<String,Integer> map = createBooksCounter();
List<String> list = map.entrySet().stream().
filter(e->e.getValue()==1).
map(e->e.getKey()).
collect(Collectors.toList());
printWhiteRavens(list);
}
public static void printWhiteRavens(List<String> whiteRavens) {
whiteRavens.stream().forEach(System.out::println);
}
您還必須編輯您的createBooksCounter方法以使用回傳地圖
return createBooksCounter;
轉載請註明出處，本文鏈接：https://www.uj5u.com/qianduan/372534.html