Then run it to make sure that the message Prints the contents of message instead of a String You may use a different string for your message if you prefer.įinally, change the println statement so that it Literal "Hello, World" into the variable named message. White space) and add an assignment statement. This statement declares message to be a variable that can holdĪ String. ForĮxample int sum declares the variable sum A variable declaration consists of aĭata type, followed by an identifier, followed by a semi-colon. In Java, a variable declaration creates a Recall that a variable can be though of as a named box Do not try toįigure out all of the errors at once! Part 3: Declaration and Assignment Remember: A good practice to follow when you have multipleĮrrors is to focus on the first error, correct it, then recompile. (Question 8) What error message(s) do you get? Put the missing brace back, and remove the semicolon at the end of the (Question 7) What was different about the errors this time? Put the brace back, then remove the closing brace after the println statement. No beginning quote mark for a string literal.(Question 6) What error message(s) do you get? No ending quote mark for a string literal.Ĭorrect the spelling in the string, then delete the opening brace at the end of this line:.(Question 5) What type of error just occurred? Now run the program, and review the "key terms" at the top of this lab. (Question 4) Why is there no error message? Next, delete one letter 'l'įrom the Welcome in the message to be printed (inside the quotation marks). (Question 3) What line number was your error on?Ĭorrect the mistake above, save, and compile. (Hello.java) and the line number in that file that contains the error. (Question 2) What error message do you get during the compile?Īll compiler messages will begin with the name of the source file (Question 1) What happens when you try to save it? Non-comment line is public class ello) and save the program. Record the answers to the following questions in your lab worksheet.ĭelete the beginning 'H' from the name of the class (so the first Produced, and in some cases, a single error will cascade several other errors. As you make each error, pay particular attention to the message This part of the lab will give you some practice in reading and interpreting Worksheet and open/edit the file as plain text. See the changes reflected in the executed program. You change and save your program, you will need to recompile the source file to You have just completed the "edit, save, compile, execute" cycle. If not, please see the instructor before proceeding. In which you placed your Hello.java file and you should see a Hello.classĮxecute your program from jGRASP by clicking the button on the toolbar.
Upon successful compilation, examine the directory (use the file browser)
Your error message will give you the line number of the first place the compiler If you have other messages indicating errors, check your typing carefully. If it compiles successfully you should see a message like the following under the "Compile Messages" tab:
JGRASP RUN PROGRAM CODE
Toolbar to indent the code and display a "Control Structure Diagram".Ĭlicking the "Remove CSD" button removes the diagram, but leaves the code properlyĬompile your Java program by clicking the button on the toolbar. Indentation makes code much easier for humans to read. Indentation doesn't matter to the Java compiler, but proper.Type in the code below into the editor window.Īll spelling, punctuation, and indentation. Open jGRASP and click "File –> New –> Java" from the menu. JGRASP is a text editor designed to simplify the process ofĮditing, compiling and executing Java programs. Key Terms source file the Java program as written by the programmer class file the executable program produced by the compiler compile process of checking syntax and producing a class file syntax error mistake in the source code that prevents compilation logic error mistake in the program that causes incorrect behavior execute the process of running a program on a computer Part 1: Java Development Cycle Recognize and correct syntax errors in a Java program. Use an IDE (Integrated Development Environment).Įdit, save, compile, and run a simple Java program.
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