Method that corrects the text, inserting spaces after the comma in Java-CodePudding

I want to create a refactorSeparators method that takes an object of the String type as an argument. Method returns the text from the input object corrected so that if there is any a comma or a period and there is no space after it, it will insert this space.I'm stuck, don't know what to do next, below is my code. How can I finish it? I wonder how to write this part: if (s.equals(".") && i.next().equals())

public class Separator {
public static void main(String[] args) {
    String text = "Periods,hyphens, the last two characters cannot be a period. The rest of them don't. And there you go.";

    ArrayList<String> stringArr = new ArrayList<>();

    String[] arrOfStr = text.split("");
    Iterator i = stringArr.iterator();


    for (String s : arrOfStr) {
        stringArr.add(s);
         System.out.println("{"  s   "}");
    }
    for (String s : arrOfStr) {
        if (s.equals(".") && i.next().equals()) {
            String space = " ";
            stringArr.add(i.next(, " ");


        } else {
            System.out.println("error");

        }

    }
}}

CodePudding user response：

You're over-thinking it:

String refactorSeparators(String str) {
    return str.replaceAll("([,.]) ?", "$1 ").trim();
}

The regex ([,.]) ? matches a comma or dot optionally followed by a space, which is replaced with the dot/comma and a space. The trim() removes the space that would be added if there's a dot at the end of the input.

CodePudding user response：

Your main problem is here:

Iterator i = stringArr.iterator();
// ...
for (String s : arrOfStr) {
    if (s.equals(".") && i.next().equals()) {

You are iterating both with an iterator and a for-loop, that makes life complicated. I'd suggest using a for-loop over the index.

Also your second equals expression is missing an argument.

Since Bohemian already posted the regex one liner, I might as well post my solution too:

public class PunctuationFixer {

    private String text;
    private int index;

    public static String addMissingWhitespaceAfterPunctuation(String input) {
        return new PunctuationFixer(input).fix();
    }

    private PunctuationFixer(String input) {
        this.text = input;
        this.index = 0;
    }

    private String fix() {
        while (index < this.text.length() - 1) {
            fix(this.text.charAt(index));
            index  ;
        }
        return this.text;
    }

    private void fix(char current) {
        if (current == '.' || current == ',') {
            addSpaceIfNeeded();
        }
    }

    private void addSpaceIfNeeded() {
        if (' ' != (text.charAt(index   1))) {
            text = text.substring(0, index   1)   " "   text.substring(index   1);
            index  ;
        }
    }

    public static void main(String[] args) {
        String text = "Periods,hyphens, the last two characters cannot be a period. The rest of them don't. And there you go.";
        System.out.println(addMissingWhitespaceAfterPunctuation(text));
    }
}

CodePudding user response：

That's an typical parse issue. You have to remember the last char you've read and deppendend on your current char, you know what to do.

    public static void main(String[] args) {
        String text = "Periods,hyphens, the last two characters cannot be a period.The rest of them don't. And there you go.";

        StringBuilder fixedString = new StringBuilder();
        String[] arrOfStr = text.split("");

        String lastChar = null;
        for(String currentChar : arrOfStr) {
            if(lastChar != null && (lastChar.equals(",") || lastChar.equals(".")) && !currentChar.equals(" "))
                fixedString.append(" ");

            fixedString.append(currentChar);
            lastChar = currentChar;
        }
        
        System.out.println(fixedString);
    }

Side note: The shortest and most elegant solution is, of course, @bohemian's. But I suspect it is not in the sense of the homework! ;-)