Implementing this interface allows an object to be the target of the "for-each loop" statement. 实现Iterable接口 允许一个对象 作为 foreach遍历的目标; 1 2 3 4 5 publicinterfaceIterable<T> { Iterator<T> iterator(); } Iterator 概述 An iterator over a collection. {@code Iterator} takes the...
packagejava.lang;publicinterfaceIterable<AnyType>{ Iterator<AnyType>iterator(); } (1)可见,Iterable接口中只包含一个方法,就是一个iterator()方法,用来返回一个Iterator类型的对象,或者说返回一个实现了Iterator接口的对象。 (2)实现了Iterable接口的类可以拥有增强的for循环,即只要实现了Iterable接口的类,就可以...
Iterable: 可迭代 Iterator: 迭代器 Iterable中包含Iterator 如部分源码 public interface Iterable<T> { /** * Returns an iterator over elements of type {@code T}. * ...
Types that implement this expanded interface can be registered explicitly using register(). 如上要点归纳: 1、sequence是定义了__getitem__()和__len__()函数的可迭代对象,内置序列有list、str、tuple、bytes,dict虽然也实现了__getitem__()和__len__()函数,但它是映射类型。 2、抽象基类collections...
The collections.abc.Sequence abstract base class defines a much richer interface that goes beyond justgetitem() andlen(), adding count(), index(),contains(), andreversed(). Types that implement this expanded interface can be registered explicitly using register(). ...
public interface Iterator<E> { /** * Returns true if the iteration has more elements. (In other * words, returns true if next would return an element * rather than throwing an exception.) * * @return true if the iterator has more elements. */ boolean hasNext(); /** * Returns ...
Collection, Iterable, and Iterator Interfaces Collection,Iterable,andIteratorInterfaces ••••TheCollectionInterfaceanditsHierarchyTheIterableandIteratorInterfacesFor-eachLoopswithIterableCollectionsReading:L&C3rd:15.1-15.22nd:3.2 1 Collections •AcollectionisatypicalexampleofAbstractDataType.•A...
() and __len(), but is considered a mapping rather than a sequence because the lookups use arbitrary immutable keys rather than integers. The collections.abc.Sequence abstract base class defines a much richer interface that goes beyond just __getitem__() and _len_(), adding count(), ...
*@returnan Iterator.*/Iterator<T>iterator(); } for-each循环可以与任何实现了Iterable接口的对象一起工作。 而java.util.Collection接口继承java.lang.Iterable,故标准类库中的任何集合都可以使用for-each循环。 Collection接口 此接口的方法 public interface Collection<E>{...} Modifier...
首先,我们还是先看下Iterator接口的定义: package java.util; public interface Iterator<AnyType> { boolean hasNext(); AnyType next(); void remove(); } 1. 2. 3. 4. 5. 6. 7. (1)当编译器见到一个正在用于Iterable对象的增强的for循环的时候,它用对iterator()方法的调用来代替增强的for循环以得到...