Java String trim has no effect

Question

Java String trim is not removing a whitespace character for me.

String rank = (some method);
System.out.println("(" + rank + ")");

The output is (1 ). Notice the space to the right of the 1.

I have to remove the trailing space from the string rank but neither rank.trim() nor rank.replace(" ","") removes it.

The string rank just remains the same either way.

Edit: Full Code::

Document doc = Jsoup.connect("http://www.4icu.org/ca/").timeout(1000000).get();
Element table = doc.select("table").get(7);
Elements rows = table.select("tr");
for (Element row: rows) {
  String rank = row.select("span").first().text().trim();
  System.out.println("("+rank+")");
}

Why can't I remove that space?

Do you use rank = rank.trim(); or just rank.trim();? The second one won't work. — Baz
– Baz, Commented Jul 28, 2012 at 11:28
@TerryLi Maybe you should give us an idea what (some method) does. — Baz
– Baz, Commented Jul 28, 2012 at 11:44
@Baz (some method) just tries to extract the ranking for each university from this site:4icu.org/ca — Terry Li
– Terry Li, Commented Jul 28, 2012 at 11:48
Please show a short but complete program demonstrating the problem. You haven't provided enough information at the moment. — Jon Skeet
– Jon Skeet, Commented Jul 28, 2012 at 11:50

Community · Accepted Answer · 2017-05-23 11:54:12Z

68

The source code of that website shows the special html character  . Try searching or replacing the following in your java String: \u00A0.

That's a non-breakable space. See: I have a string with "\u00a0", and I need to replace it with "" str_replace fails

rank = rank.replaceAll("\u00A0", "");

should work. Maybe add a double \\ instead of the \.

edited May 23, 2017 at 11:54

CommunityBot

11 silver badge

answered Jul 28, 2012 at 12:22

Baz

37k11 gold badges75 silver badges101 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

Baz Over a year ago

@TerryLi See, if you supply sufficient information, we are able to help you. Glad I could help :)

Quaternion Over a year ago

Worth noting this answer: stackoverflow.com/questions/1437933/…

Sergey Kalinichenko · Accepted Answer · 2012-07-28 11:29:24Z

7

You should assign the result of trim back to the String variable. Otherwise it is not going to work, because strings in Java are immutable.

String orig = "    quick brown fox    ";
String trimmed = original.trim();

answered Jul 28, 2012 at 11:29

Sergey Kalinichenko

729k85 gold badges1.2k silver badges1.6k bronze badges

Comments

JB Nizet · Accepted Answer · 2012-07-28 12:23:05Z

4

The character is a non-breaking space, and is thus not removed by the trim() method. Iterate through the characters and print the int value of each one, to know which character you must replace by an empty string to get what you want.

answered Jul 28, 2012 at 12:23

JB Nizet

694k94 gold badges1.3k silver badges1.3k bronze badges

Comments

Julius · Accepted Answer · 2012-07-28 11:29:19Z

2

Are you assigning the String?

String rank = " blabla "; 
rank = rank.trim();

Don't forget the second assignment, or your trimmed string will go nowhere.

You can look this sort of stuff up in the API as well: http://docs.oracle.com/javase/7/docs/api/java/lang/String.html#trim()

As you can see this method returns a String, like most methods that operate on a String do. They return the modified String and leave the original String in tact.

answered Jul 28, 2012 at 11:29

Julius

2,8946 gold badges36 silver badges57 bronze badges

Comments

Ertuğrul Çetin · Accepted Answer · 2015-07-25 08:34:06Z

I had same problem and did little manipulation on java's trim() method.
You can use this code to trim:

public static String trimAdvanced(String value) {

        Objects.requireNonNull(value);

        int strLength = value.length();
        int len = value.length();
        int st = 0;
        char[] val = value.toCharArray();

        if (strLength == 0) {
            return "";
        }

        while ((st < len) && (val[st] <= ' ') || (val[st] == '\u00A0')) {
            st++;
            if (st == strLength) {
                break;
            }
        }
        while ((st < len) && (val[len - 1] <= ' ') || (val[len - 1] == '\u00A0')) {
            len--;
            if (len == 0) {
                break;
            }
        }


        return (st > len) ? "" : ((st > 0) || (len < strLength)) ? value.substring(st, len) : value;
    }

Kishor Sharma · Accepted Answer · 2012-07-28 11:35:41Z

0

Trim function returns a new copy of the string, with leading and trailing whitespace omitted.

rank = rank.trim();// This will remove and save rank without leading and trailing spaces

will give the result you want.

Replace method will not work if you pass empty string for replacement.

answered Jul 28, 2012 at 11:35

Kishor Sharma

5998 silver badges15 bronze badges

3 Comments

Kishor Sharma Over a year ago

If you are not sure about spaces i will suggest you to use regex to extract the number. Use "((-|\\+)?[0-9]+(\\.[0-9]+)?)+" regex will extract number form string.

Terry Li Over a year ago

I'll take you advice. But I still wonder what the two spaces denote.

Baz Over a year ago

@TerryLi Unless you give us more information (like a small working program), we will never know...

heretolearn · Accepted Answer · 2012-07-28 11:36:19Z

0

Since String in java are immutable ie they cannot be changed. You need to reassign it to some temporary string. And then using that string you can convert it into int.

String temp=rank.trim()
int te= Integer.parseInt(temp)

answered Jul 28, 2012 at 11:36

heretolearn

6,5655 gold badges32 silver badges55 bronze badges

Collectives™ on Stack Overflow

Java String trim has no effect

7 Answers 7

2 Comments

Comments

Comments

Comments

Comments

3 Comments

Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

7 Answers 7

2 Comments

Comments

Comments

Comments

Comments

3 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related