String Array length is showing 1 even the array is empty after call split by comma (,) [duplicate]

Answer 1

From the doc:

If the expression does not match any part of the input then the resulting array has just one element, namely this string.

Note that this doc is from the String.split(String, int) method, which is invoked from String.split(String)

Answer 2

If you look at the implementation of String.class (refer snippet below). Here off shows the match count and this is the String currently being processed for split operation and you have ur string as serialNumbers = "";. Thats why it is returning one item in array.

        // If no match was found, return this
        if (off == 0)
            return new String[]{this};

Answer 3

serialArray contains [""], which is 1 element

Answer 4

Split always returns at least one element.

In the case that a separator is not found, the entire input is returned in a single-element array.

Answer 5

public class TestArgs {

public static void main(String[] args) {
    String checkString = "";

    System.out.println("" + splitString(checkString));



}

public static int splitString(String checkString) {
    if (checkString.indexOf(",") != -1 || !"".equals(checkString)) {
        System.out.println("hello " + checkString.split(",").length);
        return checkString.split(",").length;
    } else {
        return 0;
    }
}

}