How to find words(strings) with only Uppercase letters?

Question

I was wondering, is there any function or way, how to select from a random text all words(strings) with only uppercase letters? To be more specific, I want to take from text all uppercase words and put them into an string array, because those uppercase words are important for me.

For example from text: "This text was just made RANDOMLY to show what I MEANT."

In string array I will have words RANDOMLY and MEANT.

And array should looks like this String[] myArray = {"RANDOMLY", "MEANT"};

The only thing I think of is that I have go trought every single letter and check if its uppercase,

if yes

save the letter to a string variable
increase value of help integer variable (int count) by one
and take a look at the next letter,
- if its uppercase again, repeat this part
- if not - move to another letter.

I think my solotion is not very effective, so can tell me your opinion about it? Or prehaps how to make it more effective?

PS: int count is there for expelling short words with 3 letters and less.

Can we assume some minimal length of words you want to find? For instance do you consider `I` as correct word? Also should `U.S.A` be counted as word? — Pshemo, May 04 '15 at 19:35
Letters ending with . (dot) shouldnt be considered. Same goes for words with less than 4 letters. — Candybrk, May 04 '15 at 19:42

Pshemo · Accepted Answer · 2015-05-04T19:53:10.117

Probably easiest way to achieve it would be using regex like \b[A-Z]{4,}\b which represents

\b word boundary - place between alphanumeric and non-alphanumeric characters
[A-Z] character in range A-Z
{4,} which appears at least 4 times (if we don't want single letter words like I to be counted) (more info at: http://www.regular-expressions.info/repeat.html)
\b another word boundary to make sure that we are reading entire word

So your code could look like:

String s = "This text was just made RANDOMLY to show what I MEANT.";

Pattern p = Pattern.compile("\\b[A-Z]{4,}\\b");
Matcher m = p.matcher(s);
while (m.find()) {
    String word = m.group();
    System.out.println(word);
}

Beside printing word to console you can also store it in List<String>.

score 1 · Answer 2 · answered May 04 '15 at 19:31

1

Split your sentence by whitespace. Then you can use StringUtils.isAllUpperCase(CharSequence cs) for instance to check every single string.

http://commons.apache.org/proper/commons-lang/apidocs/org/apache/commons/lang3/StringUtils.html#isAllUpperCase(java.lang.CharSequence)

answered May 04 '15 at 19:31

swinkler

1,703
10
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2

don't forget punctuation – CupawnTae May 04 '15 at 19:33
To expand for OP: To split your sentence, use `String[] splitString= myString.split("\\s+");` Then you can iterate over the contents in the splitString, and check for `isAllUpperCase(splitString[i])` – CubeJockey May 04 '15 at 19:35
I had problems with importing libs at first but this work good aswell! Thank you – Candybrk May 05 '15 at 17:52

score 1 · Answer 3 · answered May 04 '15 at 19:45

Use Regex to extract them. Like

public static void main(String[] args) {
        List<String> words = new ArrayList<>();
        String dataStr = "This text was just made RANDOMLY to show what I MEANT.";
        Pattern pattern = Pattern.compile("[A-Z][A-Z]+");
        Matcher matcher = pattern.matcher(dataStr);
        while (matcher.find()) {
            words.add(matcher.group());
        }

        System.out.println(words);
    }

Output:

[RANDOMLY, MEANT]

With this in future, you could just adjust search pattern to extract what ever you want.

score 1 · Answer 4 · edited May 23 '17 at 12:01

Here is a solution with minimal use of regex.

String s = "This text was just made RANDOMLY to show what I MEANT.";
    String[] words = s.split(" |\\.");
    ArrayList<String> result = new ArrayList<>();

    for(String word : words) {
        String wordToUpperCase = word.toUpperCase();
        if(wordToUpperCase.equals(word)) {
            result.add(word);
        }
    }

The line of code:

String[] words = s.split(" |\\.");

means that the string will be split either by a white-space (" ") or by a dot(".")

More info on why the dashes (escaping) were needed here: Java string split with "." (dot)

If you would have split the string just by white-space, as such:

String[] words = s.split(" ");

it would have left possible nasty results like "MEANT."

In either case, the word "I" is included in the result. If you don't want that, make a check so that every word has a length greater that 1.

How to find words(strings) with only Uppercase letters?

4 Answers4