Java程序辅导

CSE114 Spring 2016
Lab Exercise 1 of Week 1
Hello World Java!
Chen-Wei Wang
1 Installing Java and Eclipse
– Download and install Java SE Development Kit Version 8 :
http://www.oracle.com/technetwork/java/javase/downloads/jdk8-downloads-2133151.html
– Download the Eclipse IDE (Integrated Development Environment):
http://www.eclipse.org/downloads/
– Choose Eclipse IDE for Java Developers to download.
– Unzip the downloaded zip file to somewhere convenient (typically C://Program Files).
– As you wish, create a shortcut to the Eclipse program contained in the unzipped folder.
– It is important that either you install the 32-bit versions for both software, or the 64-bit
versions for both, but not install mixed versions.
2 Launching Eclipse
– Double-click the Eclipse shortcut you created from the previous step.
– You may create a folder workspace that will store all your Java projects for this course.
– Select the workspace that you created, or just go with the default (typically C://Documents/workspace).
3 Exercises
1. Create a new project:CSE114 S16 Week01 Lab1
2. Create a new class HelloWorld in the project:
public class HelloWorld {
public static void main(Strng[] args) {
/* Print a greeting message. */
System.out.println("Hello World!");
}
}
3. Execute the above Java program (Right click on the class and click on Run as Java application.)
4. Modify the above program so that it outputs a different greeting message (e.g., your name).
5. Create another new class HelloWorld2 in the project:
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import java.util.Scanner;
public class HelloWorld2 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter a name to greet:");
String name = input.nextLine();
System.out.println("Hello " + name + "!");
}
}
A sample run:
Enter a name to greet:
Jackie
Hello Jackie!
6. Create another new class HelloWorld3 in the project. Adapt the above program so that it prompts
for two names, one name at a time, and greets the two persons together.
import java.util.Scanner;
public class HelloWorld3 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter the first name to greet:");
String name1 = input.nextLine();
System.out.println("Enter the second name to greet:");
String name2 = input.nextLine();
System.out.println("Hello " + name1 + " and " + name2 + "!");
}
}
A sample run:
Enter the first name to greet:
Jackie
Enter the second name to greet:
Jim
Hello Jackie and Jim!
7. Create another new class HelloWorld4 in the project. Adapt the above program so that it prompts
for a first name, greets it, prompts for a second name, and greets it.
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import java.util.Scanner;
public class HelloWorld4 {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.println("Enter the first name to greet:");
String name1 = input.nextLine();
System.out.println("Hello " + name1 + "!");
System.out.println("Enter the second name to greet:");
String name2 = input.nextLine();
System.out.println("Hello " + name2 + "!");
}
}
A sample run:
Enter the first name to greet:
Jackie
Hello Jackie!
Enter the second name to greet:
Jim
Hello Jim!
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