String abc = "a,b,c,d,,,";
String[] arr = abc.split(",");
System.out.println(arr.length);
Output is 4. But obviously my expectation is 7. Here is my solution:
String abc = "a,b,c,d,,,";
abc += "\n";
String[] arr = abc.split(",");
System.out.println(arr.length);
Why does it happen? Anyone could give my a better solution?
Use the alternative version of String#split() that takes two arguments to achieve this:
String abc = "a,b,c,d,,,";
String[] arr = abc.split(",", -1);
System.out.println(arr.length);
This prints
7
From the Javadoc linked above:
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.
split() rather than regex.You can use lookahead:
String abc = "a,b,c,d,,,";
String[] arr = abc.split("(?=,)");
System.out.println(arr.length); //7
split call, You don't need to refer to regex cookbook to get this done.split without regex support in Java.Use:
String[] arr = abc.split("(?=,)");
to split abc
This is because split does not include only trailing empty strings, but if you have \n at the end, then the last element is not empty
[a, b, c, d, , , \n]
split() is coded to that very job. You can count a character or string occurrence in the below way.
String ch = ",";
int count = 0;
int pos = 0;
int idx;
while ((idx = abc.indexOf(ch, pos)) != -1) {
++count;
pos = idx + sub.length();
}
System.out.println(count);
This very logic is used in Spring.
