private static final int DEFAULT_CAPACITY = 10; 默认长度 private static final Object[] DEFAULTCAPACITY_EMPTY_ELEMENTDATA = {}; default sized empty instances 1. new ArrayList<>() /** * Constructs an empty list with an initial capacity of ten.默认的数组长度是10 */ public ArrayList() { this...
//返回当前ArrayList实例的容量值System.out.println("这时候容量是多少："+object1.length);testList.a...
newList.add("book002");//新增集合list.addAll(1, newList); System.out.println("新增一个集合后的列表:"+ list);//返回元素最后一次出现的位置索引System.out.println("返回\"book001\"最后一次出现的位置:"+ list.lastIndexOf("book001"));//截取子集合System.out.println("返回一个范围子集合列表:...
1.ArrayList list = new ArrayList(); 会调用无参构造器,新建一个ArrayList。将elementData设置为DEFAULTCAPACITY_EMPTY_ELEMENTDATA /** * Constructs an empty list with an initial capacity of ten. */publicArrayList(){this.elementData=DEFAULTCAPACITY_EMPTY_ELEMENTDATA;} 通过源码,我们知道DEFAULTCAPACITY_EMPTY_...
实现了Deque & List接口，双向链表。transientintsize=;transientNode<E>first;transientNode<E>last;// 内部节点类privatestaticclassNode<E> {Eitem;Node<E>next;Node<E>prev;Node(Node<E>prev, Eelement, Node<E>next) {this.item=element;this.next=next;this.prev=prev;}} AbstractList抽象类中有个mod...
3. ArrayList(int initialCapacity) :Constructs an empty list with the specified initial capacity. 构造一个指定初始容量的空数组。 若调用add()方法,向一个数组中添加元素,会先调用ensureCapacityInternal()方法,该方法用来确保数组中是否还有足够容量。最后有个判断:如果剩余容量足够存放这个数据,则进行下一步,如果...
*@paraminitialCapacity the initial capacity of the list * initialCapacity 列表的初始容量 *@throwsIllegalArgumentException if the specified initial capacity * is negative * IllegalArgumentException如果指定的初始容量是负数 */publicArrayList(intinitialCapacity){super();if(initialCapacity <0)thrownewIllegalArgume...
myList is initialized with an initial capacity of 7, then the next line attempts to add the String "Hello" at position 5. This throws an IndexOutOfBoundsException: Exception in thread "main" java.lang.IndexOutOfBoundsException: Index: 5, Size: 0 I looked over this question about what "...
publicclassArrayList<E>extendsAbstractList<E>implementsList<E>,RandomAccess,Cloneable,java.io.Serializable 数组的默认大小为 10。 代码语言:java 复制 privatestaticfinalintDEFAULT_CAPACITY=10; 2. 扩容 添加元素时使用 ensureCapacityInternal() 方法来保证容量足够,如果不够时,需要使用 grow() 方法进行扩容,新容...
* Constructs an empty list with an initial capacity of ten. */ public ArrayList() { super(); this.elementData = EMPTY_ELEMENTDATA; } 我本地JDK1.7 默认数组长度是0,JDK1.6初始化大小是10 (1)添加元素,确定内部容量 /** * Default initial capacity. ...