Extract letter from String characters and numbers

Question

I have these Strings:

"Turtle123456_fly.me"
"birdy_12345678_prd.tr"

I want the first words of each, ie:

Turtle
birdy

I tried this:

 Pattern p = Pattern.compile("//d");
 String[] items = p.split(String);

but of course it's wrong. I am not familiar with using Pattern.

Possible duplicate of [How to extract a substring using regex](http://stackoverflow.com/questions/4662215/how-to-extract-a-substring-using-regex) — Stefano Zanini, Mar 09 '17 at 16:34
Better you could have used string.tochararray() and check the ASCII code you will get your answer...! — Shailesh, Mar 09 '17 at 16:35
@Shailesh Like [this example](https://www.mkyong.com/java/convert-string-to-char-array-in-java/) — Moudiz, Mar 09 '17 at 16:38

Bohemian · Accepted Answer · 2017-03-09T16:52:46.897

6

Replace the stuff you don't want with nothing:

String firstWord = str.replaceAll("[^a-zA-Z].*", "");

to leave only the part you want.

The regex [^a-zA-Z] means "not a letter", the everything from (and including) the first non-letter to the end is "removed".

See live demo.

edited Mar 09 '17 at 16:52

answered Mar 09 '17 at 16:45

Bohemian

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Then the output for `Turtle123456_fly.me` would be `Turtleflyme` not `Turtle` – Ocean15 Mar 09 '17 at 16:49
@Ocean no it wouldn't. I used `a-zA-Z`, not `\w`, and `.*` runs to the end. – Bohemian Mar 09 '17 at 16:50
Ah jeah sorry, my bad. Then this is the way to go. Way easier than the other solution – Ocean15 Mar 09 '17 at 16:52
@Ocean it's always good to question and doubt! I have added a link to a live demo to quell your concerns. – Bohemian Mar 09 '17 at 16:53

Alon Segal · Answer 2 · 2017-03-09T17:00:53.703

3

String s1 ="Turtle123456_fly.me";
String s2 ="birdy_12345678_prd.tr";

Pattern p = Pattern.compile("^([A-Za-z]+)[^A-Za-z]");
Matcher matcher = p.matcher(s1);

if (matcher.find()) {
    System.out.println(matcher.group(1));
}

Explanation: The first part ^([A-Za-z]+) is a group that captures all the letters anchored to the beginning of the input (using the ^ anchor). The second part [^A-Za-z] captures the first non-letter, and serves as a terminator for the letters sequence. Then all we have left to do is to fetch the group with index 1 (group 1 is what we have in the first parenthesis).

edited Mar 09 '17 at 17:00

answered Mar 09 '17 at 16:43

Alon Segal

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Please don't post code and tell "try this"... This community is about learning stuff, not about sharing source-code... Explain what are the main parts of the code, and what those parts of the code do, at the very least. – CosmicGiant Mar 09 '17 at 16:53

Just Me · Answer 3 · 2017-03-09T20:28:48.973

0

maybe you should try this \d+\w+.*

edited Mar 09 '17 at 20:28

answered Mar 09 '17 at 20:20

Just Me

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Extract letter from String characters and numbers

3 Answers3