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...
One such method isArrays.asList(). This method allows you to create an ArrayList and fill it with elements in a single line of code. Here’s an example: ArrayList<String>names=newArrayList<String>(Arrays.asList("John","Alice"));System.out.println(names);#Output:#[John,Alice] Java Copy...
首先来看定义的(静态)变量: classArrayList2<E>//extends AbstractList<E>//implements RandomAccess, Cloneable, java.io.Serializable{privatestaticfinallongserialVersionUID = 8683452581122892189L;privatestaticfinalintDEFAULT_CAPACITY = 10;privatestaticfinalObject[] EMPTY_ELEMENTDATA ={};privatestaticfinalObject[...
private void ensureExplicitCapacity(int minCapacity) { modCount++; // overflow-conscious code if (minCapacity - elementData.length > 0) //扩容 grow(minCapacity); } 我们先将modCount属性放到一边,看下扩容的方法grow()。 /** * Increases the capacity to ensure that it can hold at least the ...
/*** Returns {@codetrue} if the iteration has more elements. * (In other words, returns {@codetrue} if {@link#next} would * return an element rather than throwing an exception.) * *@return{@codetrue} if the iteration has more elements*/booleanhasNext();/*** Returns the next eleme...
Java系列,尽量采用通俗易懂、循序渐进的方式,让大家真正理解JDK源码的精髓! 关于JDK源码中的ArrayList类,官方文档这样描述: Resizable-arrayimplementation of the List interface. Implements all optional list operations, and permits all elements, including null. In addition to implementing the List interface, thi...
所以要强调的是:对于保存引用类型,java中的数组,和各种集合类,持有的是对象的引用,而不是对象本身。 构造函数 空ArrayList 的优化: new 一个空的ArrayList是很常见的做法,为了不让每个空ArrayList都创建一个空数组实例,ArrayList内部有一个用于共享,静态的空数组对象。当创建空的ArrayList时,内部的 elementData 就会指...
ArrayList是Java一个很常用的集合类,它相当于一个动态数组,内部的数组大小可以根据元素实际情况自动分配,也可以自己分配大小。 在使用ArrayList的时候,应注意ArrayList并不是线程安全的,如果需要多线程并发操作应当使用CopyOnWriteArrayList(读远大于写的情况),或者使用Collections工具类的synchronizedList方法将其包装。
safe variant ofArrayListin which all mutative operations (add, set, and so on) are implemented by making a fresh copy of the underlying array. This class is very useful when we cannot or do not want to synchronize the traversals of the arraylist. It is part of thread-safe Java ...
(java.io.ObjectOutputStream s) throws java.io.IOException{ // Write out element count, and any hidden stuff int expectedModCount = modCount; s.defaultWriteObject(); // Write out size as capacity for behavioural compatibility with clone() s.writeInt(size); // Write out all elements in ...