How to change spaces to underscore and make string case insensitive?

Question

I have following question. In my app there is a listview. I get itemname from listview and transfer it to the webview as a string. How to ignore case of this string and change spaces to underscores?

For example: String itemname = "First Topic". I transfer it to the next activity and want to ignore case and change space to underscore (I want to get first_topic in result). I get "itemname" in webviewactivity and want to do what I've described for following code:

String filename = bundle.getString("itemname") + ".html";

Please, help.

score 131 · Accepted Answer · edited Jul 28 '15 at 03:27

131

use replaceAll and toLowerCase methods like this:

myString = myString.replaceAll(" ", "_").toLowerCase()

edited Jul 28 '15 at 03:27

Anson VanDoren

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answered Feb 27 '12 at 07:22

shift66

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Thanks, but I have no result. I use it in activity as `String itemname = bundle.getString("itemname"); itemname.replaceAll(" ", "_").toLowerCase();` And then `String filename = itemname + ".html";` May be it's not right. Please, have a look. – Sabre Feb 27 '12 at 07:33
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u need to write it as itemname = itemname.replaceAll(" ", "_").toLowerCase(); – everconfusedGuy Feb 27 '12 at 07:41
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@naini answered... these methods are not modifying the string they just return a new modified string so you should assign the new value. – shift66 Feb 27 '12 at 07:45

score 39 · Answer 2 · edited Sep 06 '19 at 09:27

39

This works for me:

itemname = itemname.replaceAll("\\s+", "_").toLowerCase();

replaceAll("\\s+", "_") replaces consecutive whitespaces with a single underscore.

"first topic".replaceAll("\\s+", "_") -> first_topic

"first topic".replaceAll(" ", "_") -> first__topic

edited Sep 06 '19 at 09:27

Abdull

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answered Feb 07 '17 at 10:30

Chris Ociepa

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I think in most cases, your answer is better than the accepted one. – Al-Mothafar Jul 22 '19 at 08:35
This answer covers more cases it should be the accepted one – thermz Aug 16 '22 at 18:18

score 6 · Answer 3 · answered Feb 27 '12 at 07:46

6

You can use the replaceAll & toLowerCase methods but keep in mind that they don't change the string (they just return a modified string) so you need to assign the back to the variable, eg.

String itemname = bundle.getString("itemname"); 
itemname = itemname.replaceAll(" ", "_").toLowerCase(); 
String filename = itemname + ".html";

answered Feb 27 '12 at 07:46

Zarius

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Doh, question was answered as a comment to previous answer whilst I typed (and I guess I should have posted as a comment - new to StackOverflow) – Zarius Feb 27 '12 at 07:48

How to change spaces to underscore and make string case insensitive?

3 Answers3