How Can I Prevent Java's `split()` Method from Removing Empty Strings?

Fixing Empty Value Removal in Java String Splitting

When using the split() method on a Java String, you may encounter an unexpected result where empty values are removed from the resulting array. This can be seen in the following example:

String data = "5|6|7||8|9||";
String[] split = data.split("\|");
System.out.println(split.length);

In this case, you would expect to get an array of 8 values: [5, 6, 7, EMPTY, 8, 9, EMPTY, EMPTY]. However, only 6 values are returned.

The reason for this behavior is that the split() method by default removes trailing empty strings from the result array. To disable this behavior and include empty values, you can use the overloaded version of split():

String[] split = data.split("\|", -1);

By setting the limit parameter to a negative value (-1 in this case), you instruct the method to apply the pattern as many times as possible and include any trailing empty strings.

This is possible because split(regex) internally calls split(regex, 0), which removes trailing empty strings. By providing a negative limit, you effectively disable this behavior and force the method to retain all values, including empty ones.

Exception:

It's important to note that removing trailing empty strings makes sense only if they were created by the split process. For an empty String, since it cannot be split further, splitting it will result in an array with a single empty string value. This is because split() did not perform any actual splitting, so the empty string represents the original input, not an empty string generated by the splitting operation.

The above is the detailed content of How Can I Prevent Java's `split()` Method from Removing Empty Strings?. For more information, please follow other related articles on the PHP Chinese website!