I am using jdk 1.6, I am trying to run below code but it is not working as expected:
String[] arr = ",,,,,".split(",");
But length of arr is shown 0. I am expecting 6 elements in arr with all elements ""(blank) value.
Can anyone explain me reason behind this? Is there any Regular expression available to fulfil my requirement?
If you run
String[] arr = ",,,,,".split(",", -1);
the length of arr will be 6, because it also includes the empty String at the beginning.
It is working as specified in String#split() documentation. It clearly says:
Trailing empty strings are therefore not included in the resulting array.
If you want to store empty strings, use overloaded version - String.split(regex, limit):
If n is non-positive then the pattern will be applied as many times as possible and the array can have any length. If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.
So, you need to pass a negative limit here:
String[] arr = ",,,,,".split(",", -1);
You can use String#split(String regex,int limit) method.
The limit parameter controls the number of times the pattern is applied and therefore affects the length of the resulting array. If the limit n is greater than zero then the pattern will be applied at most n - 1 times, the array's length will be no greater than n, and the array's last entry will contain all input beyond the last matched delimiter. If n is non-positive then the pattern will be applied as many times as possible and the array can have any length. If n is zero then the pattern will be applied as many times as possible, the array can have any length, and trailing empty strings will be discarded.
String[] arr = ",,,,,".split(",",-1);
As per the documentation of String#split()
This method works as if by invoking the two-argument split method with the given expression and a limit argument of zero. Trailing empty strings are therefore not included in the resulting array.
Run below code:
string str = "A,B,C,D,E,F,G";
string[] arr = str.split(',');
you can get result as :
string[0] = "A"
string[1] = "B"
string[2] = "C"
string[3] = "D"
string[4] = "E"
string[5] = "F"
string[6] = "G"
I am excepted ",,,,," there is no space between two "," so when you trying to split the string , there is no string rather that ',', and split is not count the argument as a string. What you pass in argument place that String is not calculated. so it's showing length 0.
For more information please have look oracle document .
http://docs.oracle.com/javase/6/docs/api/java/lang/String.html#split%28java.lang.String%29
