Finding Upper Case in String Array and extracting it out

Question

I have an array input like this which is an email id in reverse order along with some data:

MOC.OOHAY@ABC.PQRqwertySDdd
MOC.OOHAY@AB.JKLasDDbfn
MOC.OOHAY@XZ.JKGposDDbfn

I want my output to come as

MOC.OOHAY@ABC.PQR
MOC.OOHAY@AB.JKL
MOC.OOHAY@XZ.JKG

How should I filter the string since there is no pattern?

Even if I filter all lower case letters, unwanted uppercase letters do remain which I don't want in output. — Ashish Jain, Aug 03 '15 at 08:32
If by unwanted uppercase letters you mean any letter that comes after the first lower case, then just cut everything after the first lower case. — Laurentiu L., Aug 03 '15 at 08:38

score 1 · Answer 1 · answered Aug 03 '15 at 08:32

1

Why do you think there is no pattern?

You clearly want to get the string till you find a lowercase letter.

You can use the regex (^[^a-z]+) to match it and extract.

Regex Demo

answered Aug 03 '15 at 08:32

Codebender

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score 1 · Answer 2 · answered Aug 03 '15 at 08:33

Simply split on [a-z], with limit 2:

String s1 = "MOC.OOHAY@ABC.PQRqwertySDdd";
String s2 = "MOC.OOHAY@AB.JKLasDDbfn";
String s3 = "MOC.OOHAY@XZ.JKGposDDbfn";
System.out.println(s1.split("[a-z]", 2)[0]);
System.out.println(s2.split("[a-z]", 2)[0]);
System.out.println(s3.split("[a-z]", 2)[0]);

Demo.

score 1 · Accepted Answer · answered Aug 03 '15 at 08:33

There is a pattern, and that is any upper case character which is followed either by another upper case letter, a period or else the @ character.

Translated, this would become something like this:

String[] input = new String[]{"MOC.OOHAY@ABC.PQRqwertySDdd","MOC.OOHAY@AB.JKLasDDbfn" , "MOC.OOHAY@XZ.JKGposDDbfn"};
    Pattern p = Pattern.compile("([A-Z.]+@[A-Z.]+)");
    for(String string : input)
    {
        Matcher matcher = p.matcher(string);
        if(matcher.find())
            System.out.println(matcher.group(1));
    }

Yields:

MOC.OOHAY@ABC.PQR
MOC.OOHAY@AB.JKL
MOC.OOHAY@XZ.JKG

score 0 · Answer 4 · answered Aug 03 '15 at 08:42

You can do it like this:

String arr[] = { "MOC.OOHAY@ABC.PQRqwertySDdd", "MOC.OOHAY@AB.JKLasDDbfn", "MOC.OOHAY@XZ.JKGposDDbfn" };
for (String test : arr) {
    Pattern p = Pattern.compile("[A-Z]*\\.[A-Z]*@[A-Z]*\\.[A-Z.]*");
    Matcher m = p.matcher(test);
    if (m.find()) {
        System.out.println(m.group());
    }
}

Finding Upper Case in String Array and extracting it out

4 Answers4