importjava.util.ArrayList;importjava.util.Arrays;publicclassArrayListTest{classHuman{}classMaleextendsHuman{}publicstaticvoidmain(String[]args){ArrayList<Integer>list1=newArrayList<Integer>();list1.add(1);// Appends the specified element to the end of this listlist1.add(2);list1.add(3);System....
最常用! public static Integer[] vectorToArray2(ArrayList<Integer> v) { Integer[] newText = (Integer[])v.toArray(new Integer[0]); return newText; } // toArray(T[] contents)调用方式三 public static Integer[] vectorToArray3(ArrayList<Integer> v) { Integer[] newText = new Integer[v....
println(array.remove(3));// public E set(intindex,E element)：修改指定索引处的元素，返回被修改的元素 System.out.println(array.set(1,"javaee"));// 发生索引越界异常 IndexOutOfBoundsException System.out.println(array.set(3,"javaee"));// public E get(intindex)：返回指定索引处的元...
Suppose x is a list known to contain only strings. The following code can be used to dump the list into a newly allocated array of String: String[] y = x.toArray(newString[0]); 1 Note that toArray(new Object[0]) is identical in function to toArray() Specified by: toArray in i...
assertEquals(26, stringsToSearch.lastIndexOf("a"));Copy If you want to find all elements satisfying a predicate, you may filter collection using Java 8Stream API(read more about ithere) usingPredicatelike this: Set<String> matchingStrings =newHashSet<>(Arrays.asList("a","c","9")); ...
packagej2se.demo;importjava.util.ArrayList;publicclassArrayListTest{publicstaticvoidmain(String[]args){ArrayListarrayList=newArrayList();arrayList.add("hello");arrayList.add("world");arrayList.add("java");Strings1=(String)arrayList.get(0);Strings2=(String)arrayList.get(1);Strings3=(String)arrayList...
代码语言:java 复制 ArrayList<String> substrings = new ArrayList<>(); substrings.add(str.substring(0, 5)); // 添加子字符串到ArrayList substrings.add(str.substring(5, 10)); substrings.add(str.substring(10, 15)); // 遍历ArrayList中的子字符串 for (String subStr : substrings) { System...
Can be used for the largest number of other kinds of data structures. This example uses an Iterator to print all elements (Strings) in an ArrayList. It uses hasNext(), which returns true if there are more elements, and next(), which returns the next element. Works with both ArrayList ...
(1)); //IndexOutOfBoundsException // System.out.println(array.remove(3)); //public E set(int index,E element):修改指定索引处的元素,返回被修改的元素 // System.out.println(array.set(1,"javaee")); //IndexOutOfBoundsException // System.out.println(array.set(3,"javaee")); //public...
System.out.println(listofStrings.getClass().getCanonicalName()); // java.util.Arrays.ArrayList 使用new ArrayList(Arrays.asList(array)) 创建的List的类型是java.util.ArrayList类。我们将一个列表包装器传递给ArrayList构造函数,构造函数会从中实际复制所有元素并创建一个新的独立的ArrayList对象。