A Java brainteaser for you

[Dave Alvarado]

Hi,

I'm using Java 1.5 with the PMD code-checker. It is currently complaining about this method ...

	public int getNumResults() {
		return this.budgetExpenseRecord != null ? 1 : 0; 
	}	// getNumResults

because it says, "Avoid if (x != y) ... else". However if I change the method to

	public int getNumResults() {
		int numResults = 0;
		if (this.budgetExpenseRecord != null) { 
			numResults = 1;
		}	// if
		return numResults;
	}	// getNumResults

it complains about a 'DD anomaly', because numResults gets defined in different scopes. Any idea how to write this method to satisfy this thing?

Thanks, - Dave

[Paul Clapham]

It has a symmetry fetish? Then like this, maybe?

	public int getNumResults() {
		int numResults;
		if (this.budgetExpenseRecord != null) { 
			numResults = 1;
		} else {
			numResults = 0;
		}
		return numResults;
	}

[Paul Clapham]

Or perhaps this in response to the first complaint:

	public int getNumResults() {
		return this.budgetExpenseRecord == null ? 0 : 1; 
	}

[Dave Alvarado]

Hi Paul, Thanks for your suggestions. I modified your first solution to read

	public int getNumResults() {
		int numResults;
		if (this.budgetExpenseRecord == null) {
			numResults = 0;
		} else {
			numResults = 1;
		}
		return numResults;
	}

and the warnings went away. Thanks! - Dave

[David Newton]

Yuck.

DD anomalies can often be safely ignored (as it explains); consider turning off the check, using a comment-based switch, or something else.

[Paul Clapham]

Well, I do agree that logic of the form

"If not X then do Y else do Z"

is usually easier to understand if it's written as

"If X then do Z else do Y"

although there are specific exceptions to that general statement.

[David Newton]

Agreed; I'm just yucking about the if/else expression that's more expressive as a ternary.