Java List Iterator

Iterator and iterable objects in Java. Let's take a look at the difference between these two objects and how to implement the for each loop in a custom class.

Java Iterator is an interface that provides only the basic rules for iteration, and a foreach loop can be used for any container that implements the Iterable interface.

Java iterator is mainly used to manipulate collection objects in java. Java provides an iterator interface Iterator. Iterator can only move forward and cannot be rolled back.

Java Iterable interface and the Iterator interface. The class that implements the Iterable interface is iterable; the class that implements the Iterator interface is an iterator.

This article describes the use of java iterators to traverse ArrayList collections, Set collections, and Map collections.

Often we want to delete some elements in the collection.　　Some might write that. public void operate (List list) {for (Iterator it = List.iterator (); It.hasnext ();)　　{String str = (string) it.next (); if (Str.equals ("Chengang")) {list ....

Spark conversion (transform) and Action (action) list. The following func, most of the time, to make logic clearer, we recommend using anonymous functions! (lambda) "" "Ps:java and Python APIs are the same, names and parameters are unchanged." Transform meaning Map (func) Each INPUT element is exported after a Func function conversion and output an element filter (func) returns the value returned after the Func function evaluates to The input element of true is composed of ...

After completing the four basic learning steps of Apache Cassandra, you can try the actual code. If necessary, it is recommended to briefly review: Apache Cassandra Learning Step (1) Apache Cassandra Learning Ste ...

A brief introduction to MapReduce and HDFs what is Hadoop?     &http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp; Google has proposed a programming model for its business needs mapreduce and Distributed File system Google file systems, and published related papers (available in Google Research ...).

What is Hadoop? Google proposes a programming model for its business needs MapReduce and Distributed file systems Google File system, and publishes relevant papers (available on Google Research's web site: GFS, MapReduce). Doug Cutting and Mike Cafarella made their own implementation of these two papers when developing search engine Nutch, the MapReduce and HDFs of the same name ...