string - How to capitalize first letter and lowercase the rest while keeping the word capital if it is in fully uppercase - java

Question

getSentenceCaseText()

return a string representation of current text in sentence case. Sentence case is the conventional way of using capital letters in a sentence or capitalizing only the first word and any proper nouns. In addition, all capital word should remain as it is.

For this assignment, noun is limited to words that have ONE capital letter at the beginning.

**As an example the string "First SenTence. secOND sentence. tHIRD SENTENCE"

its output will be (First sentence. Second sentence. Third SENTENCE)**

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This is my code for the above assignment. I could capitalize the first letter after every dot and set the rest as lowercase but i couldn't find out how to keep full uppercase word as it is.

This is my code below:

public String getSentenceCaseText(String text) { 
    
    int pos = 0;
    boolean capitalize = true;
    StringBuilder sb = new StringBuilder(text);
    
    while (pos < sb.length()){
         sb.setCharAt(pos, Character.toLowerCase(sb.charAt(pos)));
         if (sb.charAt(pos) == '.') {
            capitalize = true;      
        } else if (capitalize && !Character.isWhitespace(sb.charAt(pos))) {
            sb.setCharAt(pos, Character.toUpperCase(sb.charAt(pos)));   
            capitalize = false;
        }
        pos++;
       }   
   return sb.toString();
}
    

question from:https://stackoverflow.com/questions/65891480/how-to-capitalize-first-letter-and-lowercase-the-rest-while-keeping-the-word-cap

Answer 1

Most of the logic that you have posted works fine. The problem is words like "SENTENCE" because the logic that you are using to check the capitalization is incorrect.

The biggest problem is that you are trying to iterate over the words and check at the same time if that string is or not capitalize.

The easiest way is to separate concerns; try to check beforehand if the word is or not capitalized and act accordingly.

First create a method that just checks if a word is or not capitalized. For example:

public static boolean isUpper(String s, int start) {
    for(int i = start; i < s.length(); i++) {
        char c = s.charAt(i);
        if(c == '.' || c == ' ')
            return true;
        if (!Character.isUpperCase(c))
            return false;
    }
    return true;
}

This method receives a string (to be checked) and an int value (i.e., start) that tells the method from which part of the string should the checking start.

For the getSentenceCaseText method follow the following strategy. First check if the current word is capitalized:

 boolean capitalize = isUpper(text, pos);

if is capitalized the method should skip this word and move to the next one. Otherwise, it capitalizes the first character and lowers the remaining. Apply the same logic to all words in the text.

The code could look like the following:

public static String getSentenceCaseText(String text) {
    int pos = 0;
    StringBuilder sb = new StringBuilder(text);

    // Iterate over the string
    while (pos < sb.length()){
        // First check if the word is capitalized 
        boolean capitalize = isUpper(text, pos);
        char c = sb.charAt(pos);

        // Make the first letter capitalized for the cases that it was not 
        sb.setCharAt(pos, Character.toUpperCase(c));
        pos++;

        // Let us iterate over the word
        // If it is not capitalized let us lower its characters
        // otherwise just ignore and skip the characters 
        for (;pos < sb.length() && text.charAt(pos) != '.' && text.charAt(pos) != ' '; pos++)
            if(!capitalize)
                sb.setCharAt(pos, Character.toLowerCase(sb.charAt(pos)));
       
       // Finally we need to skip all the spaces
       for(; pos < sb.length() && text.charAt(pos) == ' '; pos++ );
    }

    return sb.toString();
}

Use this strategy and this code as guide, build upon it and implement your own method.