Embedded Files
Unit 2 Greenfoot A3 Revision Sheet.pdfMain revision sheet
New WJEC GCSE_Computer_Science Booklet Greenfoot.pdfUse the IDE to help with your Syntax
Use the IDE to help with your Syntax
In Greenfoot IDE you can press Ctrl + Space, to see a list of methods within that class (and Actor or World). If the method you wish to use is not in that Class then type the Class name, followed by a space, then press Ctrl + Space e.g. Greenfoot.
Common ErrorS and how to solve them
Common ErrorS and how to solve them
Left image show the error message and right image shows correction.
{ missing
{ missing
Look for the colours (layers of the cake), open { and closing } brackets are needed for:
if (grey)
methods (yellow)
classes (green)
Corrected
Corrected
Open { on if was missing
. (dot) missing
. (dot) missing
The dot is missing between the Class and the method.
CORRECTED
CORRECTED
The . (dot) between Greenfoot and isKeyDown() method has been added
Syntax Error - naming
Syntax Error - naming
Classes need to start with capitals (e.g. Greenfoot), methods start with lowercase and use camelCase (e.g. isKeyDown(String)
CORRECTED
CORRECTED
getRandomNumber(int) had a captial to start the method
) missing
) missing
Closing braket missing from method call.
Corrected
Corrected
Closing bracket of turn method missing
( Missing
( Missing
Opening bracket of method call missing
Corrected
Corrected
( Opening bracket of move missing
Counter ErrorS AND HOW TO SOLVE THEM
Counter ErrorS AND HOW TO SOLVE THEM
If you attempt the Counter, and your code doesn't work you will get zero marks. So make sure you remove errors or comment out the code with // to make the instructions comments.
() Missing
() Missing
Creating a new instance (version) of a class needs to be written:
ClassName variable = new ClassName();
This runs the constructor in that class when the new object is created.
CORRECTED
CORRECTED
() added to create a new Counter
TIP: Can't remember this call? Always go to the World Class e.g. Ground for that game, then look at the prepare() method to see how new objects are created.
(new) Missing
(new) Missing
new is missing from creating the object
CORRECTED
CORRECTED
new added to create a new Counter
TIP: Can't remember this call? Always go to the World Class e.g. Ground for that game, then look at the prepare() method to see how new objects are created.
NO ERROR MESSAGE BUT...
NO ERROR MESSAGE BUT...
private and non static used for any attributes (variables) in the Counter Class.
CORRECTED
CORRECTED
public static used on totalCount
TIP: Remember all attributes used to update the Counter need these. In other briefs this has been more than one attribute, e.g.
value and target (see main revision sheet)
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