Core Java的那点事儿之ArrayList 万丈高楼平地起,Java基础要拿起.今天就从我看的Core Java里找了些小基础点来分享一下. 首先隆重介绍一下专业级龙套演员---Employee类(PS:我可是专注龙套30年),下面会有多次出场,因此先在此介绍一下: class Employee{ private String name; private double salary; private int id; //下面是set.get方法 } ArrayList 首先有请ArrayL…

Difference between Vector and Arraylist is the most common  Core Java Interview question you will come across in Collection .  This question is mostly used as a start up question by the Interviewers before testing deep  roots of  the Collection  .Vec…

4.7. PackagesJava allows you to group classes in a collection called a package. Packages are convenient for organizing your work and for separating your work from code libraries provided by others.The standard Java library is distributed over a numbe…

文章首发于[博客园-陈树义],点击跳转到原文Java日志框架那些事儿. 在项目开发过程中,我们可以通过 debug 查找问题.而在线上环境我们查找问题只能通过打印日志的方式查找问题.因此对于一个项目而言,日志记录是一个非常重要的问题.因此,如何选择一个合适的日志记录框架也非常重要. 在Java开发中,常用的日志记录框架有JDKLog.Log4J.LogBack.SLF4J.SLF4J.这些日志记录框架各有各的特点,各有各的应用场景.了解这些框架的特点及应用场景,有利于我们做技术选型的时候做出正确…

二.数组列表 —— ArrayList 1.构造方法 ArrayList 是 Java 中的动态数组,底层实现就是对象数组,只不过数组的容量会根据情况来改变. 它有个带 int 类型参数的构造方法,根据传入的参数,扩展初始化的数组容量,这个方法是推荐使用的,因为如果预先知道数组的容量,可以设置好初始值,而不用等每次容量不够而扩容,减少 Arrays.copyOf 的次数: 它的很多方法的实现都是依靠 Arrays 这个工具类完成的,足以体现它与数组之间的密切关系. 比如有个带 Collectio…

We are sharing 25 java interview questions , these questions are frequently asked by the recruiters.Java questions can be asked from any core java topic . So we try our best to provide you the java interview questions and answers for experienced whic…

java怎么用一行代码初始化ArrayList 您可以创建一个工厂方法: public static ArrayList<String> createArrayList(String ... elements) {  ArrayList<String> list = new ArrayList<String>();   for (String element : elements) {    list.add(element);  }  return list;} ..…

import java.awt.BorderLayout; import java.awt.EventQueue; import java.awt.Font; import java.awt.Graphics; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.net.URL; import javax.swing.JApplet; import javax.swing.JBu…

1.2. The Java "White Paper" BuzzwordsThe authors of Java have written an influential White Paper that explains their design goals and accomplishments. They also published a shorter summary that is organized along the following 11 buzzwords:1. Si…

翻译自:How to Convert Array to ArrayList in Java? 本文分析了Stack Overflow上最热门的的一个问题的答案,提问者获得了很多声望点,使得他得到了在Stack Overflow上做很多事情的权限.这跟我没什么关系,我们还是先看看这个问题吧. 这个问题是”在Java中怎样把数组转换为ArrayList?” Element[] array = {new Element(1),new Element(2),new Element(3)}; 1.最流行也…