Now we have a special type of Iterator that is only for List Interface which is known as ListIterator. It is even better Iterator for a List containing more utility methods like getting index of elements and adding elements to the base object. Using ListIterator we can iterate in both the ...
不使用 Iterator 遍历集合是这样的: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 for(int i=0; i<集合的大小;i++){ // ... } 使用Iterator 遍历集合是这样的: 代码语言:javascript 代码运行次数:0 运行 AI代码解释 Iterator iterator = list.iterator(); while (iterator.hasNext()){ System...
In Java, theArrayList.listIterator()returns aListIteratorthat iterates over the elements of the current list. AListIteratoris a bi-directional iterator that is fail-fast in nature. By default, elements returned by the list iterator are in proper sequence. 1.ArrayList.listIterator()Method Thelis...
Example 1: Implementation of ListIterator In the example below, we have implemented thenext(),nextIndex()andhasNext()methods of theListIteratorinterface in anarray list. importjava.util.ArrayList;importjava.util.ListIterator;classMain{publicstaticvoidmain(String[] args){// Creating an ArrayListArrayL...
1. List<data type> list = new ArrayList<data type>(); // General sysntax. For example: a. List<String> list = new ArrayList<String>(); // Creating a list of objects of String type using ArrayList. b. List<Integer> list = new LinkedList<Integer>(); Creating a list of objects ...
Iterator with Generics Example In the above section we discussed about ClassCastException. Lets see what is it and why it occurs when we don’t use Generics. importjava.util.ArrayList;importjava.util.Iterator;publicclassIteratorDemo2{publicstaticvoidmain(Stringargs[]){ArrayListnames=newArrayList()...
Java 提供的 集合类都在 Java.utils 包下,其中包含了很多 List, Set, Map, Queue… 它们的关系如下面这张类图所示: 可以看到,Java 集合主要分为两类:Collection 和 Map. 而 Collection 又继承了 Iterable< E > 接口,Iterable 接口内只有一个 iterator 方法,返回一个 Iterator 迭代器: ...
Using iterator Using enhanced for-each loop. Using list iterator Using for loop Using forEachRemaining() method. ArrayList Size We can usesize()method of ArrayList to find thenumber of elements in an ArrayList. importjava.util.ArrayList;publicclassJavaExample{publicstaticvoidmain(String[]args){Arr...
Iterator<Object[]> i = rowList.iterator(); while (i.hasNext()) { Object[] databaseRow1 = (Object[])i.next(); for (loop = 0; loop < dataItemsList.length; loop++) System.out.println(databaseRow1[loop]); } Listing 5 Using an Iterator with an ArrayList Object The first line in...
ListIterator While loop Iterable.forEach() util Stream.forEach() util Java Example: You need JDK 13 to run below program aspoint-5above usesstream()util. voidjava.util.stream.Stream.forEach(Consumer<? super String> action) performs an action for each element of this stream. ...