Java String token

Question

I have read the String.split Javadoc, and I also read How to split a string in Java

I was trying this code, and my delimiters are

!,?._'@

However, it doesn't split. What's wrong with my code?

import java.io.*;
import java.util.*;

public class Solution {
  public static void main(String[] args) 
  { 
    String[] tokens = "He is a very very good boy, isn't he?".split(" !,\\?\\._'@");
    for (String token : tokens){
      System.out.println(token);
    }
  }
}

The output should be

He
is
a
very
very
good
boy
isn
t
he

But instead, I get

He is a very very good boy, isn't he?

Elliott Frisch · Answer 1 · 2016-03-13T05:37:42.250

4

You need to separate your regular expression delimiters into a character class grouping (the | symbol means or, while the + means one or more). Something like,

String[] tokens = "He is a very very good boy, isn't he?"
        .split("[ |!|,|\\?|\\.|_|'|@|]+");
for (String token : tokens) {
    System.out.println(token);
}

which outputs (as requested)

He
is
a
very
very
good
boy
isn
t
he

edited Mar 13 '16 at 05:37

answered Mar 13 '16 at 05:02

Elliott Frisch

198,278
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249

ohk understood..but one thing..will you please tell me why the exclamation,? and _ are between pipes???these aren't special characters right? – Rahul Singh Mar 13 '16 at 05:08
1

The `|` is part of the character class group; it means **or**. – Elliott Frisch Mar 13 '16 at 05:10
@Elliott..i have edited the output.Actually i don't want a space between boy and isn.Since we use both space and , as delimiters why is it still giving the space? – Rahul Singh Mar 13 '16 at 05:20
Because you have `, ` which is two consecutive delimiters. Add a `+` to the class. – Elliott Frisch Mar 13 '16 at 05:37
got it now..thanks..Elliott..:) – Rahul Singh Mar 13 '16 at 05:54

Rishi · Accepted Answer · 2016-03-13T06:57:12.333

2

Edited :

public class Solution {
 public static void main(String[] args) 
    {

       String[] tokens = "He is a very very good boy, isn't he?".split("[ |!|,|\\?|\\.|_|'|@|]+");
       for(String token : tokens){
       System.out.println(token);
       }
      }
     }

Try this out...

edited Mar 13 '16 at 06:57

answered Mar 13 '16 at 05:03

Rishi

1,163
7
12

@Rishi..Actually I don't want a space between boy and isn?I have edited the output. – Rahul Singh Mar 13 '16 at 05:23
1

I have edited the code, just use "+" after the regex, which says as match 1 or more characters of this type. – Rishi Mar 13 '16 at 05:39
This code doesn't work. It lacks the `|` to make the regular expression an *or*. – Elliott Frisch Mar 13 '16 at 06:26
@Elliott : I have edited it now. Thank you for pointing out. – Rishi Mar 13 '16 at 06:28
@Rishi Why `import java.util.*`? – Elliott Frisch Mar 13 '16 at 06:39

Java String token

2 Answers2