1 / 8

Java Intro

Java Intro. A First Java Program. //The Hello, World! program in Java public class Hello { public static void main(String[] args) { System.out.println("Hello, World!"); } }. A First Java Program. //The Hello, World! program in Java Comments start with //

willena
Télécharger la présentation

Java Intro

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Java Intro

  2. A First Java Program //The Hello, World! program in Java public class Hello { public static void main(String[] args) { System.out.println("Hello, World!"); } }

  3. A First Java Program • //The Hello, World! program in Java • Comments start with // • Comment goes to the end of the line • Multiline comments start with /* and end with */ • /*This is a multiline • comment */

  4. A First Java Program • public class Hello { • } • Definition for the class Hello • Class Hello MUST be defined in a file named Hello.java • The class definition is enclosed in {}

  5. A First Java Program • public static void main(String[] args) { • } • Every Java application must have a main method • The header of every main method looks the same • The method is enclosed by {} • Whitespace is ignored • Proper indentation is not required by the compiler • But, it is required by the instructor...

  6. A First Java Program • System.out.println("Hello, World!"); • Print the string enclosed by the quotation marks • Every statement must end with a semi-colon • Double quotes enclose strings

  7. Java Compiler High-level Code Bytecode Interpreter (JVM) Output

  8. Writing/Compiling/Running • Write the program using your favorite text editor – save a class classname into file classname.java • Open a terminal window and cd into the directory where your code is saved • To compile, type javac classname.java • Fix any errors and go back to step 3 • To run, type java classname

More Related