Reduce length of condition [closed]

Question

Is there a way to reduce this lengthy if condition:

if(
    statusCode.equals( NO_ERRORS_NO_WARNINGS ) ||
    statusCode.equals( HAS_ERRORS_NO_WARNINGS )  ||
    statusCode.equals( HAS_ERRORS_HAS_WARNINGS ) ||
    statusCode.equals( NO_ERRORS_HAS_WARNINGS )
){
    //do something
}

The purpose of it is to see if there is a status code set within a log file. So the String statusCode could be a null value, one of the 4 status codes above or an unpredicatable String.

Answer 1

First of all, if statusCode can be null, the code above could possibly throw a null pointer exception.

To directly answer your question though, you could use a Set, such as a HashSet.

HashSet<String> errorOrWarning = new HashSet<String>();
errorOrWarning.add(HAS_ERRORS_HAS_WARNINGS);
errorOrWarning.add(HAS_ERRORS_NO_WARNINGS);
errorOrWarning.add(HAS_ERRORS_HAS_WARNINGS);
errorOrWarning.add(NO_ERRORS_HAS_WARNINGS);

Which you can then use in a single call.

if (errorOrWarning.contains(statusCode) {
    // do something
}

This has the advantage that statusCode can be null and it would produce no exception.

Answer 2

I'm not sure about your class design, but I recommend refactoring this into some easier to use properties. I'm assuming we're within a class:

public boolean hasErrors() {
    return statusCode != null && (statusCode.equals(HAS_ERRORS_HAS_WARNINGS)
        || statusCode.equals(HAS_ERRORS_NO_WARNINGS));
}

public boolean hasWarnings() {
    return statusCode != null && (statusCode.equals(HAS_ERRORS_HAS_WARNINGS)
        || statusCode.equals(NO_ERRORS_HAS_WARNINGS));
}

That does not buy you much in withing those functions, but later on comes in handy:

if(hasErrors() || hasWarnings()) {
    // Do something
}

Answer 3

If you have a large number of such conditions, it may be just easier to use arrays for the same, (as in the above comment)

for(T i : new T[]{HAS_ERRORS_HAS_WARNINGS, HAS_ERRORS_NO_WARNINGS, HAS_ERRORS_HAS_WARNINGS, NO_ERRORS_HAS_WARNINGS}) 
  if statusCode.equals(i) {
    // do
    break;
  }

Note - not as efficient as above, - O(n)

(you could also assign that to a variable and reuse the array if the same pattern is expected elsewhere.)

Answer 4

Use StringUtils.equalsAny:

if (StringUtils.equalsAny(statusCode, NO_ERRORS_NO_WARNINGS, 
        HAS_ERRORS_NO_WARNINGS, HAS_ERRORS_HAS_WARNINGS, 
        NO_ERRORS_HAS_WARNINGS)) {
    //do something
}

Unfortunately this method is not part any official release but the code is in the JIRA, you can copy it.

/**
 * Verifies if the tested string is equal with any of the provided strings.
 * This method is null safe and case sensitive.
 * 
 * @param str Tested string
 * @param any Strings to be tested against.
 * @return true if tested string is equal to any of the provided strings. false otherwise.
 */
public static boolean equalsWithAny(final String str, final String... any) {
    if (str == null) {
        return false;
    }

    if (any == null) {
        return false;
    }

    for (final String s: any) {
        if (str.equals(s)) {
            return true;
        }
    }

    return false;
}