replaceAll, how to change letters

Question

What would I need instead of "" to replace all alphabetical letters with * ?

public static void main(String[] args) {
    String s = "Tere, TULNUKAS, 1234!";
    String t = asenda(s); // "****, ********, 12345!" <---- example 
}

public static String asenda(String s) {
    return s.replaceAll("", "*");
}

Thanks!

Beware of any non-English characters with that regex... a far better idea is the Unicode letter category: `\\p{L}`. — Marko Topolnik, Jan 14 '14 at 12:36

score 4 · Answer 1 · answered Jan 14 '14 at 12:35

4

You have to use regular expression:

return s.replaceAll("[a-zA-z]", "*")

answered Jan 14 '14 at 12:35

Jakub Kubrynski

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score 2 · Answer 2 · answered Jan 14 '14 at 12:33

2

For every letter you can use the [a-zA-Z] regex

For example:

public static String asenda(String s) {
    return s.replaceAll("[a-zA-Z]", "*");
}

answered Jan 14 '14 at 12:33

Konstantin Yovkov

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@RohitJain Yet it isn't a plain string, either. Something to watch out for :) – Marko Topolnik Jan 14 '14 at 12:35
@MarkoTopolnik Didn't understand your comment. :( – Rohit Jain Jan 14 '14 at 12:37
@RohitJain `$` and `\ ` are special chars there. Try making a regex to replace each `\ ` with `\\ ` :) – Marko Topolnik Jan 14 '14 at 12:39
@MarkoTopolnik Indeed. `$` is used for referencing capture groups. :) – Rohit Jain Jan 14 '14 at 12:47

score 2 · Answer 3 · edited May 23 '17 at 12:03

Proper solution with unicode characters support is

public static String asenda(String s) {
    return s.replaceAll("\\p{L}", "*");
}

You can match a single character belonging to the "letter" category with \p{L}.

Source: Unicode Regular Expressions/Unicode Categories

More information:

replaceAll, how to change letters

3 Answers3