This question already has answers here:
How do I split a string in Java?
(39 answers)
Closed 7 years ago.
I would like to parse entire file based on all the possible delimiters like commas, colon, semi colons, periods, spaces, hiphens etcs.
Suppose I have a hypothetical string line "Hi,X How-how are:any you?" I should get output array with items Hi,X,How,how,are,any and you.
How do I specify all these delimiter in String.split method?
Thanks in advance.
String.split takes a regular expression, in this case, you want non-word characters (regex \W) to be the split, so it's simply:
String input = "Hi,X How-how are:any you?";
String[] parts = input.split("[\\W]");
If you wanted to be more explicit, you could use the exact characters in the expression:
String[] parts = input.split("[,\\s\\-:\\?]");
Related
This question already has answers here:
How to Split a mathematical expression on operators as delimiters, while keeping them in the result?
(5 answers)
Closed 4 years ago.
I want to split a mathematical function by the sign of the variables in it like this :
input--> x-5y+3z=10
output--> [x,-5y,+3z,=10]
this code does not work in the way i want :
String function = "x-5y+3z=10";
String split = function.split("=|-|\\+");
the output of the array is :
[x,5y,3z,10]
so what is the correct regex for this ?
The "problem" using split is that the delimiter used will be removed, because it'll takt the parts that are between this delimiter, you need a pattern that is non-capturing or with a simple lookahead : match something wich is before something else
The pattern (?=[-+=]) would work, it'll take the part that starts with a -+= symbol without removing it :
String function = "x-5y+3z=10";
String[] split = function.split("(?=[-+=])");
System.out.println(Arrays.toString(split)); //[x, -5y, +3z, =10]
Some doc on Lookahead
This question already has answers here:
Splitting a Java String by the pipe symbol using split("|")
(7 answers)
Closed 7 years ago.
I have a file with content
1|yes|
2|yes|
3|yes|
4|yes|
5|yes|
6|yes|
7|yes|
8|yes|
9|yes|
10|yes|
11|yes|
12|yes|
13|yes|
14|yes|
15|yes|
I use java's String[] tokens = split("|"); to split each line, but it returns (for example splitting "10|yes|") [1,0,|,y,e,s,|]. It seems instead of splitting by "|", it splits every character. Anyone has any idea on it? Thanks!
split accepts a regular expression. | has a specific meaning in regular expressions, it expresses an alternation. To actually split on |, you have to escape it in the regex with a backslash. Since you specify the regex using a string literal, and backslashes are special in string literals, you have to escape that with another backslash:
String[] tokens = str.split("\\|");
In the general case, if you want to use the contents of a string literally, you can use Pattern.quote to automatically escape any special characters. You don't really need it here, but it's useful for end-user-entered values:
String[] tokens = str.split(Pattern.quote(stringToSplitOnLiterally));
This question already has answers here:
Splitting a Java String by the pipe symbol using split("|")
(7 answers)
Closed 7 years ago.
I want to split an android string to smaller ones with any | char.
Just imagine I have this long string :
This|is|a|long|string|in|java
So, I wanna split it. I need to get a array in output with this values :
[1]=>"This"
[2]=>"is"
[3]=>"a"
[4]=>"long"
[5]=>"string"
[6]=>"in"
[7]=>"java"
I have tried :
separated = oldstring.split("|");
But, i didn't give me the thing i need!
How can i do that? Any code can do that?
Note that String's split() method take regex as a param. Not string.
public String[] split(String regex)
Since | is a meta character, and it's have a special meaning in regex.
It works when you escape that.
String separated[] = oldstring.split("\\|");
This question already has answers here:
How to split a comma separated String while ignoring escaped commas?
(6 answers)
Closed 9 years ago.
I'm looking for a regular expression to match , but ignore \, in Java's regex engine. This comes close:
[^\\],
However, it matches the previous character (in addition to the comma), which won't work.
Perhaps the regular expression approach is the wrong one altogether. I was intending to use String.split() to parse a simple CSV file (can't use an external library) with escaped commas.
You need a negative look-behind assertion here:
String[] arr = str.split("(?<![^\\\\]\\\\),");
Note that you need 4 backslashes there. First escape the backslash for Java string literal. And then again escape both the backslashes for regex.
This question already has answers here:
How can I use "." as the delimiter with String.split() in java [duplicate]
(8 answers)
Closed 9 years ago.
I am trying to do a String.split on a website address using the "." so that I can find the domain name of the website.
However, when I do this:
String href = "www.google.com";
String split[] = href.split(".");
int splitLength = split.length;
It tells me that the splitLength variable is 0. Why is this, and how can I make this work?
Try using this to split the string:
href.split("\\.");
Explanation: split splits on a regex, not on a regular substring. In regexes, . is the metacharacter for 'match any character', which we don't want. So we have to escape it using a backslash \. But \ is also a metacharacter for escaping in Java strings, so we need to escape it twice.
Split uses a regex so do:
String split[] = href.split("\\.");