Removing whitespaces from strings in java?

Question

This code seems like it should remove the spaces, it removes everything but the lowercase letters like I want, but for some reason the spaces stay. What am I doing wrong?

for(int i = 0; i < message.length(); i++){      
    if((int) message.charAt(i) > 122 || (int) message.charAt(i) < 97)
        message = message.replace(message.charAt(i), Character.MIN_VALUE);      
}   
String msg = message.replaceAll("\s", "");

Change the '\\s' to '\\s+' \\s is whitespace \\s+ or \\s++ is any amount of whitespace — , Nov 26 '17 at 18:07
I am printing out msg right after, and it prints out the string exactly as I want, except the spaces aren't removed. — Ian, Nov 26 '17 at 18:08
`String msg = message.replaceAll("\\s", "");` Should work fine. You do not need that for loop to just remove spaces (Don't know what you were trying to do with that one). — nicovank, Nov 26 '17 at 18:08
The for loop is to remove all characters besides lowercase letters, and it works for everything but spaces. For some reason, the spaces stay in the string, that is my problem. — Ian, Nov 26 '17 at 18:10
In the for-loop you replace the spaces by zero. If you print the message, these zeros will be displayed as empty spaces. — mayamar, Nov 26 '17 at 18:19
You're changing `message` in the loop, but assigning the no-whitespace string to `msg`; are you reading `msg` or `message` when you say it doesn't remove whitespace? — Andy Turner, Nov 26 '17 at 18:49
`message = message.replaceAll("[^a-z]", "");` would work correctly, and wouldn't leave any whitespace to have to remove subsequently. — Andy Turner, Nov 26 '17 at 18:50

Stephan D. · Answer 1 · 2017-11-26T18:46:59.653

-1

Try this :) This create a new string containing no whitespace. And if you need to do it more than once make this to a simple method that returns a string.

String resultStr = "";    
for(int i = 0; i < message.length(); i++){      
       if (!Character.isWhitespace(message.charAt(i)))
       resultStr += message.charAt(i);
    }   

// without whitespace
System.out.print(resultStr);

edited Nov 26 '17 at 18:46

answered Nov 26 '17 at 18:15

Stephan D.

254
2
12

You could do it more effecient with ascii codes instead :) – Stephan D. Nov 26 '17 at 18:16
Any reason to use String instead of StringBuilder here? – Ivan Gammel Nov 26 '17 at 18:18
Nope I just like it simple :) – Stephan D. Nov 26 '17 at 18:19
1

Let's avoid "try this" code dump answers. At least *explain* what you're doing what the problem is. Make the answer useful to more than just the OP. Please comment back once fixed. – Hovercraft Full Of Eels Nov 26 '17 at 18:22
Hope it fits you – Stephan D. Nov 26 '17 at 18:34
2

Note that this doesn't remove whitespace, it just removes *some* whitespace. Use `Character.isWhitespace(message.charAt(i))` as the condition to handle all whitespace. – Andy Turner Nov 26 '17 at 18:34
1

@Marc.9 you don't need to cast a char to an int (it is widened automatically); and using `' '` is preferable to using a magic number. – Andy Turner Nov 26 '17 at 18:36

Removing whitespaces from strings in java?

1 Answers1