### 计算机代写|Java代写|The Java Development Kit

Java是一种广泛使用的计算机编程语言，拥有跨平台、面向对象、泛型编程的特性，广泛应用于企业级Web应用开发和移动应用开发。

statistics-lab™ 为您的留学生涯保驾护航 在代写Java方面已经树立了自己的口碑, 保证靠谱, 高质且原创的统计Statistics代写服务。我们的专家在代写Java代写方面经验极为丰富，各种代写Java相关的作业也就用不着说。

• Statistical Inference 统计推断
• Statistical Computing 统计计算
• (Generalized) Linear Models 广义线性模型
• Statistical Machine Learning 统计机器学习
• Longitudinal Data Analysis 纵向数据分析
• Foundations of Data Science 数据科学基础

## 计算机代写|Java代写|The Java Development Kit

Now that the theoretical underpinning of Java has been explained, it is time to start writing Java programs. Before you can compile and run those programs, you must have a Java Development Kit (JDK). At the time of this writing, the current release of the JDK is JDK 17. This is the version for Java SE 17. (SE stands for Standard Edition.) It is also the version described in this book. Because JDK 17 contains features that are not supported by earlier versions of Java, it is recommended that you use JDK 17 (or later) to compile and run the programs in this book. (Remember, because of Java’s faster release schedule, JDK feature releases are expected at six-month intervals. Thus, don’t be surprised by a JDK with a higher release number.) However, depending on the environment in which you are working, an earlier JDK may already be installed. If this is the case, then newer Java features will not be available.
The JDK supplies two primary programs. The first is javac, which is the Java compiler. The second is java, which is the standard Java interpreter and is also referred to as the application launcher. One other point: The JDK runs in the command-prompt environment and uses command-line tools. It is not a windowed application. It is also not an integrated development environment (IDE).

## 计算机代写|Java代写|Entering the Program

The programs shown in this book are available from www.mhprofessional.com. However, if you want to enter the programs by hand, you are free to do so. In this case, you must enter the program into your computer using a text editor, not a word processor. Word processors typically store format information along with text. This format information will confuse the Java compiler. If you are using a Windows platform, you can use Notepad or any other programming editor that you like.
For most computer languages, the name of the file that holds the source code to a program is arbitrary. However, this is not the case with Java. The first thing that you must learn about Java is that the name you give to a source file is very important. For this example, the name of the source file should be Example.java. Let’s see why.

In Java, a source file is officially called a compilation unit. It is a text file that contains (among other things) one or more class definitions. (For now, we will be using source files that contain only one class.) The Java compiler requires that a source file use the .java filename extension. As you can see by looking at the program, the name of the class defined by the program is also Example. This is not a coincidence. In Java, all code must reside inside a class. By convention, the name of the main class should match the name of the file that holds the program. You should also make sure that the capitalization of the filename matches the class name. The reason for this is that Java is case sensitive. At this point, the convention that filenames correspond to class names may seem arbitrary. However, this convention makes it easier to maintain and organize your programs. Furthermore, as you will see later in this book, in some cases, it is required.

## 计算机代写|Java代写|A Second Simple Program

Perhaps no other construct is as important to a programming language as the assignment of a value to a variable. A variable is a named memory location that can be assigned a value. Further, the value of a variable can be changed during the execution of a program. That is, the content of a variable is changeable, not fixed. The following program creates two variables called myVar1 and myVar2:
$/ *$
This demonstrates a variable.
Call this file Example2.java.

• $/$
class Example2 {
public static void main(string [] args) {
int myVarl; // this declares a variable 4-Declare variables.
int myVar2; $/ /$ this declares another variable
myVarl = $1024 ; / /$ this assigns 1024 to myVarl – Assign a variable a value.
System.out. println (“myVarl contains ” + myVarl);
$m y \operatorname{Var} 2=m y \operatorname{Var} 1 / 2 ;$
System. out. print (“myVar2 contains myVar1/2:”);
System. out. println (myVar2);
)
}
When you run this program, you will see the following output:
myVarl contains 1024
myVar2 contains myVarl/ $/ 2: 512$
This program introduces several new concepts. First, the statement
int myvarl; // this declares a variable
declares a variable called myVar1 of type integer. In Java, all variables must be declared before they are used. Further, the type of values that the variable can hold must also be specified. This is called the type of the variable. In this case, myVar1 can hold integer values. These are whole number values. In Java, to declare a variable to be of type integer, precede its name with the keyword int. Thus, the preceding statement declares a variable called myVar1 of type int.

## 计算机代写|Java代写|The Java Development Kit

JDK 提供了两个主要程序。第一个是 javac，它是 Java 编译器。第二个是java，它是标准的Java解释器，也被称为应用程序启动器。另一点：JDK 在命令提示符环境中运行，并使用命令行工具。它不是一个窗口应用程序。它也不是集成开发环境 (IDE)。

## 计算机代写|Java代写|A Second Simple Program

/∗

• /
类 Example2 {
public static void main(string [] args) {
int myVarl; // 这声明了一个变量 4-Declare variables.
诠释 myVar2;//这声明了另一个变量
myVarl =1024;//这将 1024 分配给 myVarl – 为变量赋值。
系统输出。println (“myVarl 包含” + myVarl);
米是曾是⁡2=米是曾是⁡1/2;
系统。出去。打印（“myVar2 包含 myVar1/2:”）；
系统。出去。println (myVar2);
)
}
当你运行这个程序时，你会看到如下输出：
myVarl contains 1024
myVar2 contains myVarl//2:512
该程序引入了几个新概念。一、声明
int myvarl；// 这声明了一个变量
，声明了一个名为 myVar1 的整数类型的变量。在 Java 中，所有变量都必须在使用前声明。此外，还必须指定变量可以保存的值的类型。这称为变量的类型。在这种情况下，myVar1 可以保存整数值。这些是整数值。在 Java 中，要将变量声明为整数类型，请在其名称前加上关键字 int。因此，前面的语句声明了一个名为 myVar1 的 int 类型变量。

## 有限元方法代写

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## MATLAB代写

MATLAB 是一种用于技术计算的高性能语言。它将计算、可视化和编程集成在一个易于使用的环境中，其中问题和解决方案以熟悉的数学符号表示。典型用途包括：数学和计算算法开发建模、仿真和原型制作数据分析、探索和可视化科学和工程图形应用程序开发，包括图形用户界面构建MATLAB 是一个交互式系统，其基本数据元素是一个不需要维度的数组。这使您可以解决许多技术计算问题，尤其是那些具有矩阵和向量公式的问题，而只需用 C 或 Fortran 等标量非交互式语言编写程序所需的时间的一小部分。MATLAB 名称代表矩阵实验室。MATLAB 最初的编写目的是提供对由 LINPACK 和 EISPACK 项目开发的矩阵软件的轻松访问，这两个项目共同代表了矩阵计算软件的最新技术。MATLAB 经过多年的发展，得到了许多用户的投入。在大学环境中，它是数学、工程和科学入门和高级课程的标准教学工具。在工业领域，MATLAB 是高效研究、开发和分析的首选工具。MATLAB 具有一系列称为工具箱的特定于应用程序的解决方案。对于大多数 MATLAB 用户来说非常重要，工具箱允许您学习应用专业技术。工具箱是 MATLAB 函数（M 文件）的综合集合，可扩展 MATLAB 环境以解决特定类别的问题。可用工具箱的领域包括信号处理、控制系统、神经网络、模糊逻辑、小波、仿真等。