So I've finally finished my coding for my project and I'm busy tiding up my code. I was wonder if Arduino has a explicit option like VB.net or some other option to let you know if you have variables defined that you aren't using?
Is there such a option?
IDE version?
The latest - v1.0
• Start the Arduino IDE
• Click the File menu item then click Preferences
• Ensure Show verbose output during: compilation is checked
• Click OK
Test sketch...
void setup( void )
{
int notused;
}
void loop( void )
{
}
Result...
sketch_feb17a.cpp: In function 'void setup()':
sketch_feb17a.cpp:7: warning: unused variable 'notused'
Thanks - as easy as that.
It works finding for unused variables declared in a void, but not if you declare a variable outside of it. Eg I put
int test = 1;
before the:
void setup() {
}
And it does not report that its unused.
Put static in front of the variable definition.
Awesome - thanks. That did it.
declared in a void,
They're called "functions", not "void"s.
If the function returned an "int", you wouldn't call it an "int"
Cool - another learnt tonight 
Keep in mind also that the compiler is going to do away with unused variables under the hood. I applaud your desire to keep your code clean however, it definitely promotes better code to do things like that.
It works finding for unused variables declared in a void, but not if you declare a variable outside of it. Eg I put
And it does not report that its unused.
That's because it is not unused. If you explicitly define a value, you are using the variable.
If you know what value the variable should have, then you know that you are going to use it.