找到 4330 篇文章 关于 Java 8
131 次浏览
首先,让我们创建一个 Java Map 并进行初始化 -Map map = new HashMap(); map.put(1, "Tom"); map.put(2, "John"); map.put(3, "Kevin"); map.put(4, "Jacob"); map.put(5, "Ryan");现在,将 Map 转换为 List -ArrayList key = new ArrayList(map.keySet()); ArrayList value = new ArrayList(map.values());示例以下是在 Java 中将 Map 转换为 List 的程序 -import java.util.HashMap; import java.util.ArrayList; import java.util.Map; public class Demo { public static void main(String args[]) { Map map = new HashMap(); map.put(1, "Tom"); map.put(2, "John"); map.put(3, "Kevin"); map.put(4, "Jacob"); map.put(5, "Ryan"); ... 阅读更多
92 次浏览
假设以下为我们的字符串 -String str = "My String";现在,将以上内容转换为 IntStream -IntStream stream = str.chars();示例以下是在 Java 中将字符串转换为 IntStream 的程序 -import java.util.stream.IntStream; public class Demo { public static void main(String[] args) { String str = "My String"; System.out.println("String: " + str); IntStream stream = str.chars(); System.out.println("IntStream..."); stream.forEach(System.out::println); } }输出String: My String IntStream... 77 121 32 83 116 114 105 110 103
101 次浏览
让我们首先创建一个 IntStream -IntStream stream = "Ryan".chars();现在,将此 IntStream 转换为字符串 -String str = stream.collect(StringBuilder::new,StringBuilder::appendCodePoint,StringBuilder::append).toString();示例以下是在 Java 中将 IntStream 转换为字符串的程序 -import java.util.stream.IntStream; public class Demo { public static void main(String[] args) { IntStream stream = "Ryan".chars(); String str =stream.collect (StringBuilder::new,StringBuilder::appendCodePoint,StringBuilder::append).toString(); System.out.println("String (IntStream to string) = " + str); } }输出String (IntStream to string) = Ryan
699 次浏览
首先创建一个 HashMap -Map map = new HashMap(); map.put("1", "One"); map.put("2", "Two"); map.put("3", "Three"); map.put("4", "Four"); map.put("5", "Five"); map.put("6", "Six");现在,将以上 HashMap 转换为 TreeMap -Map treeMap = new TreeMap(); treeMap.putAll(map);示例以下是在 Java 中将 HashMap 转换为 TreeMap 的程序 -import java.util.*; import java.util.stream.*; public class Demo { public static void main(String args[]) { Map map = new HashMap(); map.put("1", "One"); map.put("2", "Two"); map.put("3", "Three"); map.put("4", "Four"); map.put("5", "Five"); map.put("6", "Six"); ... 阅读更多
132 次浏览
装箱数组是以对象形式定义的数组,而不是基本类型。示例以下是在 Java 中将装箱数组转换为流的程序 -import java.util.*; import java.util.stream.*; public class Demo { public static void main(String args[]) { String arr[] = { "Laptop", "Mobile", "Notebook", "Desktop" }; System.out.println("Array = "+ Arrays.toString(arr)); Streams = Stream.of(arr); System.out.println("Stream (array to stream) = "+ Arrays.toString(s.toArray())); } }输出Array = [Laptop, Mobile, Notebook, Desktop] Stream (array to stream) = [Laptop, Mobile, Notebook, Desktop]
734 次浏览
首先,让我们设置一个字符串的 ArrayList -ArrayList arrList = new ArrayList(); arrList.add("Bentley"); arrList.add("Audi"); arrList.add("Jaguar"); arrList.add("Cadillac");现在,使用 toArray() 转换为字符串数组 -int size = arrList.size(); String res[] = arrList.toArray(new String[size]);示例以下是在 Java 中将字符串的 ArrayList 转换为字符串数组的程序 -import java.util.*; public class Demo { public static void main(String[] args) { ArrayList arrList = new ArrayList(); arrList.add("Bentley"); arrList.add("Audi"); arrList.add("Jaguar"); arrList.add("Cadillac"); arrList.add("Mazda"); arrList.add("Land Rover"); arrList.add("Porsche"); ... 阅读更多
482 次浏览
首先,设置一个包含字符串值的列表 -List myList = new ArrayList( Arrays.asList("One", "Two", "Three", "Four"));现在,使用 String.join() 将它们设置为逗号分隔的列表 -String str = String.join(", ", myList);示例以下是在 Java 中将字符串转换为逗号分隔的列表的程序 -import java.util.*; public class Demo { public static void main(String args[]) { List myList = new ArrayList(Arrays.asList("One", "Two", "Three", "Four")); System.out.println("List = " + myList); // 逗号分隔 String str = String.join(", ", myList); System.out.println("String (Comma Separated) = " ... 阅读更多
506 次浏览
首先,创建一个字符串的 Set -Set setStr = new HashSet(Arrays.asList("osCommerce", "PrestaShop", "Magento", "Wordpres", "Drupal"));现在,使用 toArray() 方法转换为字符串数组 -String[] arrStr = setStr.toArray(new String[0]);示例以下是在 Java 中将字符串的 Set 转换为字符串数组的程序 -import java.util.Arrays; import java.util.Set; import java.util.HashSet; public class Demo { public static void main(String[] args) { Set setStr = new HashSet( Arrays.asList("osCommerce", "PrestaShop", "Magento", "Wordpres", "Drupal")); System.out.println("Set of String: " + setStr); String[] arrStr = setStr.toArray(new String[0]); System.out.println("Array ... 阅读更多
614 次浏览
假设我们有以下 ArrayList:List arrList = Arrays.asList("John", "Jacob", "Kevin", "Katie", "Nathan");现在,使用 toCollection() 将此 ArrayList 转换为 LinkedList:List myList = arrList.stream().collect(Collectors.toCollection(LinkedList::new));示例以下是用 Java 将 ArrayList 转换为 LinkedList 的程序:import java.util.*; import java.util.stream.*; public class Demo { public static void main(String args[]) { List arrList = Arrays.asList("John", "Jacob", "Kevin", "Katie", "Nathan"); System.out.println("ArrayList = " + arrList); List myList = arrList.stream().collect(Collectors.toCollection(LinkedList::new)); System.out.println("LinkedList (ArrayList to LinkedList) = " + myList); } }输出ArrayList = [John, Jacob, Kevin, Katie, Nathan] LinkedList (ArrayList to ... 阅读更多