Program doesn't run in Eclipse

Question

I'm learning Java and one of the examples of the book runs perfectly from command line, but throws an error from Eclipse. The script is this:

 /**
 * This program displays a greeting from the authors.
 * @version 1.20 2004年02月28日
 * @author Cay Horstmann
 */
 public class Welcome
 {
 public static void main(String[] args)
 {
 String[] greeting = new String[3];
 greeting[0] = "Welcome to Core Java";
 greeting[1] = "by Cay Horstmann";
 greeting[2] = "and Gary Cornell";
 for (String g : greeting)
 System.out.println(g);
 }
 }

The error I get in Eclipse is 'Exception in thread "main" java.lang.Error: Unresolved compilation problem: Syntax error, 'for each' statements are only available if source level is 1.5 or greater' The book says I would get an error in that line (the for) if the JDK was too old, but then why does it run well from the command line? Thanks

• Nick Humrich: You probably haven’t set up your jdk for eclipse at all. Make sure you go into your class path and verify it has a reference to your jdk.
• azurefrog: You probably have a version of java newer than 1.5 installed in JAVA_HOME, but have your compiler compliance level < 1.5 in your eclipse settings.
• EyeOfTheHawks: Try this: stackoverflow.com/questions/1944468/…

Answer 1

Right click on your project --> properties and change version in below screen

enter image description here

• Haniver: Thank you. That did it. Now how do I change the default compiler version for future projects?
• upog: click on that particular project and then properties...Then Java version will be updated to that particular project

Answer 2

The reason is because your Eclipse instance uses a different version of Java compared to when run from the command line. In order to check which java version is being used as default, type java -version on the command prompt

C:>java -version
java version "1.6.0_45" Java(TM) SE Runtime Environment (build 1.6.0_45-b06) Java HotSpot(TM) Client VM (build 20.45-b01, mixed mode, sharing)

In order to check the Java version that your eclipse instance uses, check out

Welcome Project-->Properties--> Java Build Path--> Libraries--> JRE System Library.

You can verify the Java version for your project from the package explorer as well. enter image description here