There is notraditional for loopin Kotlin unlike Java and other languages. In Kotlin,forloop is used to iterate through ranges, arrays, maps and so on (anything that provides an iterator). The syntax offorloop in Kotlin is: for (item in collection) { // body of loop } ...
System.out.println("iteratorLoop Time="+(end-start)); } 运行结果:forLoop Time=368 4.foreach loop(java 8) privatevoidforEachLoop(){ List<Integer> a =prepareData(loopSize);longstart=System.currentTimeMillis(); a.forEach(item->item.toString());longend=System.currentTimeMillis(); System....
for (Iterator<String> itr = birds.iterator(); itr.hasNext();) { String bird = itr.next(); } 从性能角度来看,这种方式还好,获取每个元素都是固定时间,但是,从代码风格来看,略显复杂了。 不过,iterator有个优点,就是可以在循环体内删除列表中的元素(可能成功-依赖List的具体实现),而其他的2种方式不行。
InJava 8, with the introduction ofFunctional InterfaceΛ’s, Java architects have provided us with an Internal Iterator (forEach loop) supported byCollection frameworkand can be used with the collections object. This method performs a given action for each element of the collection. Let’s see ...
Java的三种循环：foreach，Iterator和classicforloop 不得不说，java语⾔在提供了这三种循环⽅式带来灵活性的同时，同时也将⼀些“混乱”引⼊了进来。这⾥的“混乱”并不是真正意义上的混乱，⽽是由于没有统⼀的风格⽽带来使⽤习惯的问题——想象⼀下，如果同⼀个项⽬中这三种都有⼈⽤，...
package java.lang; import java.util.Iterator; /** * Instances of classes that implement this interface can * be used with the enhanced for loop. * @since 1.5 */ public interface Iterable<T> { /** * Returns an {@link Iterator} for the elements in ...
以下是一个简单的 Java 程序，使用 for 循环输出数字 0 到 9：public class ForLoopExample { public...
引用变量名的java语句; } 官网解释: for (TimerTask t : c) t.cancel(); When you see the colon (:) read it as “in.” The loop above reads as “for each TimerTask t in c.” As you can see, the for-each construct combines beautifully with generics. It preserves all of the type...
For-Each 是 Java5 中引入的另一种数组遍历技术,它以类似于常规for循环的关键字开头具有以下特点: 无需声明和初始化循环计数器变量,而是声明一个与数组的基本类型相同类型的变量,然后是冒号,然后是冒号,然后是数组名。 在循环主体中,可以使用创建的循环变量,而不是使用索引数组元素。
// use a predefined inputstream iterator: InputStreamIterable it = new InputStreamIterable( LoopElimination.class.getResourceAsStream("/testfile.txt")); StreamSupport.stream(it.spliterator(), false) .forEach(ch -> System.out.print(ch)); 如果你经常遇到此类while循环，那么你可以创建并使用一个...