The Split() Method in Java Does Not Work on a Dot (.)

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("\\.").

Java .split(|) not working

Use escape character before | like below:

String[] res = "12345|6".split("\\|");

Similar "escape character logic" is required, when you are
dealing/splitting with any of the below special characters (used by
Regular Expression):

• OR sign (|)
• question mark (?)
• asterisk (*)
• plus sign (+)
• backslash (\)
• period (.)
• caret (^)
• square brackets ([ and ])
• dollar sign ($)
• ampersand (&)

String.split on dot doesn't work as expected

split uses regex and in regex . means "any character beside line separators".

So you split on each character creating array full of empty elements like

"foo".split(".")

would at first create ["","","",""], but since split also trails empty elements placed at the end of array you would get empty array []. Trailing last empty strings can be turned off with overloaded version of split split(regex,limit) by passing negative value as limit.

To solve this problem you need to escape .. To do this you can use for instance

• split("\\.") - standard escape in regex
• split("[.]") - escaping using character class
• split("\\Q.\\E") - \Q and \E mark area in which regex metacharacters should be treated as simple literals
• split(Pattern.quote(".")) - this method uses Pattern.LITERAL flag inside regex compiler to point that metacharacters used in regex are simple literals without any special meaning

Another problem would be condition in your for loop but more about it in Jeroens answer.

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 for '$' not working

String.split() takes in regex as argument and $ is a metacharacter in Java regex API. Therefore, you need to escape it:

String splitString = "122$23$56$rt";
for(int i=0;i<splitString.split("\\$").length;i++){
   System.out.println("I GOT IS :: "+splitString.split("\\$")[i]);
}

Other metacharacters supported by the Java regex API are: <([{\^-=!|]})?*+.>

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 in java does not work?

String input = ":-) :) :o) :] :3 :c) :> =] 8) =) :} :^)";
String[] similies = input.split(" ");
for (String simili : similies) {
    System.out.println(simili);
}

This works fine.
Output :

:-)
:)
:o)
:]
:3
:c)
:>
=]
8)
=)
:}
:^)

and in case if there is any tab/newline/spaces and you wnat to split, in that case you can use

input.split("\\s+"); 

in your example there is few more charaters are their like  and non breaking whitespaces so you have to explicitly handle these type of charater. Here is the code:

public static void main(final String[] args) throws Exception {
    BufferedReader fileReader = new BufferedReader(new FileReader("emoticon.txt"));
    String line = "";
    while ((line = fileReader.readLine()) != null) {
        line = line.replaceAll("Â", "");
        line = line.replace("" + ((char) 160), " ");
            System.out.println("line: " + line);
        String[] icons = line.split("\\s+");
        for (String icon : icons) {
            System.out.println(icon);
        }
        System.out.println("=======================");
    }
}

String's split function doesn't

You need to escape the period, i.e., it must be temp.split("\\.").

Otherwise, it will treat period as "any character".
Since any character matches all characters of your string, your complete string becomes only separators. Since separators are left out of the split result, the split result is empty. This is why you get the out of bounds exception.

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