Splitting a string and extracting specific strings to array

Question

I am having a String "S".Only Substrings in single quotes must be assigned to a String Array.Its may not be necessary alternate words are in single quotes.

String S = "Username 'user1'
             Username2 'user2'
             Usermane3 'user3' 'user4'";

It must be assigned as below (only Substrings with single Quotes)

 String Username[] ={'user','user1','user2','user4'};

What I tried

 String s1 = S.replace(System.getProperty("line.separator"), " ");
   //replacing newline with single space
 String Username[] = s1.split(" ");
  //separating string into sub-string
 Username[]={Username,'user1',Username2,'user2',Username3, 'user3','user4'};

A simple google query "how to split a string in java" gave me the link to the SO post [How to split a string in Java](http://stackoverflow.com/questions/3481828/how-to-split-a-string-in-java) — LBes, Aug 31 '15 at 06:55
@LBesacon I am looking for solution to extract substrings in single quotes not to looking how to split. — Ravichandra, Aug 31 '15 at 07:15

Uma Kanth · Accepted Answer · 2015-08-31T08:43:13.683

7

You could split the input using a delimiter and take the alternate strings.

String S = "Username 'user1' Username2 'user2 user21' Usermane3 'user3'";
String[] tokens = S.split("'");//use delimiter as ' to get the value inside the quote
String[] usernames = new String[tokens.length / 2];
for (int i = 1, k = 0; i < tokens.length; i += 2) {
    System.out.println(tokens[i]);
    usernames[k++] = tokens[i];
}

If there is no rule that a Single Username would have a single user1 like

String S = "Username 'user1' Username2 'user2' Usermane3 'user3' 'user4'";

You could use a logic to get only the strings in the quotes as below.

String S = "Username 'user1' Username2 'user2' Usermane3 'user3' 'user4'";
ArrayList<String> words = new ArrayList();
String word = "";
boolean startQuote = false;
for (int i = 0; i < S.length(); ++i) {
    char ch = S.charAt(i);
    if (ch == '\'') {
        if (word.equals(""))
            startQuote = true;
        else {
            words.add(word);
            word = "";
            startQuote = false;
            }
        }
    else if (startQuote) {
        word += ch;
    }
}
System.out.println(words);

edited Aug 31 '15 at 08:43

answered Aug 31 '15 at 06:53

Uma Kanth

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Thankyou but I am looking for solution to extract substrings in single quotes. (its not necessary alternate words are in single quotes substrings). – Ravichandra Aug 31 '15 at 07:06
That was not specified in the question. I'll update my answer – Uma Kanth Aug 31 '15 at 07:08
Dear I updated my Question... – Ravichandra Aug 31 '15 at 07:21
@Ravichandra I updated my answer check it out. – Uma Kanth Aug 31 '15 at 08:24
@Ravichandra I added few more detailed version to accept all other cases. Please have a look at it. – Uma Kanth Aug 31 '15 at 08:43
I am using Arrays.tostring(Username); to print.. – Ravichandra Aug 31 '15 at 08:53

score 0 · Answer 2 · answered Aug 31 '15 at 07:02

0

This will pretty print the array as described in @Uma Kanth's version. If you need it to.

System.out.print("usernames = [");
for (int i = 0; i < usernames.length; i++) {
    String username = usernames[i];
    System.out.print(username);
    if (i < usernames.length - 1) {
        System.out.print(", ");
    }
}
System.out.println("]");

answered Aug 31 '15 at 07:02

Craig

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3
24
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2

But Its not answer for my problem. Instead of all above u can use System.out.println(Arrays.toString(usernames)); – Ravichandra Aug 31 '15 at 07:30
Thanks @Ravichandra I didn't know that trick! – Craig Aug 31 '15 at 07:30

Splitting a string and extracting specific strings to array

2 Answers2