CODEWITHSUNDEEP
javastringcharacterpunctuation
Eragon20
Eragon20

Reputation: 483

Removing all characters but letters in a string

If I have a string "ja.v_,a", how can I remove all non-letter characters to output "java"? I have tried str = str.replaceAll("\\W", "" ), but to no avail.

Upvotes: 4

Views: 7356

Answers (4)

Mikhail Antonov
Mikhail Antonov

Reputation: 1367

I would like to refer to this article and quote it:

Regex examples and tutorials always give you the [a-zA-Z0-9]+ regex to "validate alphanumeric input". It is built-in in many validation frameworks. And it is so utterly wrong. This is a regex that must never appear anywhere in your code, unless you have a pretty good explanation. Yet, the example is ubiquitous. Instead, the right regex is [\p{L}0-9]+

So in your case it would be:

str.replaceAll("[^\\p{L}]", "");
System.out.println("ja.v_,a".replaceAll("[^\\p{L}]", ""));
System.out.println("сл-=о-_=во!".replaceAll("[^\\p{L}]", ""));

Where \p{L} is the Unicode definition of a "letter".

Upvotes: 4

kannadasan
kannadasan

Reputation: 11

String test= "ja.v_,a";

int len=test.length();

String alphaString="";

for(int i=0; i<len; i++){
     if (Character.isLetter(test.charAt(i))) {
         alphaString=alphaString+test.charAt(i);
     }
}

System.out.println(alphaString);

Upvotes: 1

Roma Khomyshyn
Roma Khomyshyn

Reputation: 1152

Could you try this one?

System.out.println("ja.v_,a".replaceAll("[^a-zA-Z]", "")) //java

Upvotes: 4

Olin Blodgett
Olin Blodgett

Reputation: 188

String s = "ja.v_,a";
s = s.replaceAll("[^a-z]", "");
System.out.println(s);

>java

Upvotes: 0

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