Java String Split with "." (Dot)

Java string split with . (dot)

You need to escape the dot if you want to split on a literal dot:

String extensionRemoved = filename.split("\\.")[0];

Otherwise you are splitting on the regex ., which means "any character".

Note the double backslash needed to create a single backslash in the regex.

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You're getting an ArrayIndexOutOfBoundsException because your input string is just a dot, ie ".", which is an edge case that produces an empty array when split on dot; split(regex) removes all trailing blanks from the result, but since splitting a dot on a dot leaves only two blanks, after trailing blanks are removed you're left with an empty array.

To avoid getting an ArrayIndexOutOfBoundsException for this edge case, use the overloaded version of split(regex, limit), which has a second parameter that is the size limit for the resulting array. When limit is negative, the behaviour of removing trailing blanks from the resulting array is disabled:

".".split("\\.", -1) // returns an array of two blanks, ie ["", ""]

ie, when filename is just a dot ".", calling filename.split("\\.", -1)[0] will return a blank, but calling filename.split("\\.")[0] will throw an ArrayIndexOutOfBoundsException.

Split function with dot on string in java

Try this

String arr[] = dob.split("\\.");

ie, you need to put the double slash to escape the dot as dot will match any character in regex. Also note that double backslash is used to create a single backslash in regex.

String split by dot - Java

This handles all delim values:

String str = "21.12.2015";
String delim = ".";   // or "-" or "?" or ...
String[] st = str.split(java.util.regex.Pattern.quote(delim));

String split with Dot character not working

Did you escape the dot? string.split("\\.") or string.split("[.]")

Split string with dot as delimiter

split() accepts a regular expression, so you need to escape . to not consider it as a regex meta character. Here's an example :

String[] fn = filename.split("\\."); 
return fn[0];

spliting a string by space and dot and comma at the same time

The method split can be used with a Regex pattern, so you can match more elaborated cases to split your string.

A matching pattern for your case would be:

[ \.,]+

Regex Exaplanation:

[ .,]+ - The brackets create Character Set, that will match any character in the set.

[ .,]+ - The plus sign is a Quantifier, it will match the previous token (the character set) one or more times, this solves the problem where the tokens are following one another, creating empty strings in the array.

You can test it with the following code:

class Main {
  public static void main(String[] args) {
    String str = "Hello, World!, StackOverflow. Test Regex";
    String[] split = str.split("[ .,]+");
    for(String s : split){
      System.out.println(s);
    }    
  }
}

The output is:

Hello

World!

StackOverflow

Test

Regex

How to split a string on a 'dot' if, and only if, the preceding and following char is not a 'dot'

This regex would work:

s.split("(?<!\\.)\\.(?!\\.)");  

The idea is to use negative lookahead to only split at "." which is not followed or preceded by another dot.

How can I split by the last point of a String?

Use myString.lastIndexOf(".") to get the index of the last dot.

For example, if you are sure that your input String contains at least one dot :

String name = myString.substring(0,myString.lastIndexOf("."));

The split() method in Java does not work on a dot (.)

java.lang.String.split splits on regular expressions, and . in a regular expression means "any character".

Try temp.split("\\.").

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