All MethodsInstance MethodsConcrete Methods 解析ArrayList的构造函数 //默认构造函数,默认容量大小为10ArrayList()//capacity是ArrayList的默认容量大小。每次扩容为原来的1.5倍。ArrayList(intcapacity)//创建一个包含collection的ArrayList,可以将别的ArrayL
import java.util.ArrayList; public class RunoobTest { public static void main(String[] args) { ArrayList<String> sites = new ArrayList<String>(); sites.add("Google"); sites.add("Runoob"); sites.add("Taobao"); sites.add("Weibo"); sites.remove(3); // 删除第四个元素 System.out.print...
Methods in ArrayList MethodDescription add(E e) This method adds an element to the end of the list. add(int index, E element) This method adds an element to the list at the specifed index. addAll(Collection c) This method adds the elements of the specified collection to the end of th...
list1.addAll(list2); 3. boolean addAll(int index, Collection c):此方法用于在列表中的指定位置添加一组元素。例如: list1.addAll(2, list2): // Adding all elements of list2 at position index 2 in list1 4. void add(int index, Object o):用于在列表中的特定位置索引处添加一个元素。例如...
Here’s an example of using some of these methods: ArrayList<String>names=newArrayList<String>();names.add("John");names.add("Alice");names.set(0,"Bob");names.remove(1);System.out.println(names);#Output:#[Bob] Java Copy In this example, we first created an ArrayList named ‘names’...
retainAll(objects); } java.utilArrayListretainAll Javadoc Retains only the elements in this list that are contained in the specified collection. In other words, removes from this list all of its elements that are not contained in the specified collection. Popular methods of ArrayList <init> ...
Resizable-array implementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, this class provides methods to manipulate the size of the array that is used internally to store the list. (This ...
The implementation of all these examples and code snippetscan be found over onGithub– this is a Maven-based project, so it should be easy to import and run as it is. Get started with Spring 5 and Spring Boot 2, through theLearn Springcourse:...
We have seen a few methods of the ArrayList class before likeadd(),addAll(),remove(),set(),iterate()andclear(). Today we will see thecontains()method. If we need to check if any element is present in the list or not, we can use thecontains()method from the ArrayList class in J...
Methods inherited from class java.util.AbstractCollection containsAll,toString Methods inherited from class java.lang.Object finalize,getClass,notify,notifyAll,wait,wait,wait Methods inherited from interface java.util.List containsAll,equals,hashCode