How to correctly print unicode math powers

user_12603460 0
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I would like to format a number raised to a power using unicode characters. The thing is that I have to parse first a String containing ^ symbols and the powers next to it

I understand that if, for example I get x^2 to format it I should basically System.out.println("x\u00B2") for printing x²

What if I get a 2 digit power such as x^23 ?

I have the following code for formatting 1 digit powers:

//0, 1, 2, 3, 4, 5, 6, 7, 8, 9
 char[] unicodePowers = {'\u2070','\u00B9','\u00B2','\u00B3','\u2074',
            '\u2075','\u2076','\u2077','\u2078','\u2079'};
 String[] resultPowers = {"^0","^1","^2","^3","^4","^5","^6","^7","^8","^9"};

 for(int i = 0; i < unicodePowers.length; i++){
     expression = expression.replace(resultPowers[i],String.valueOf(unicodePowers[i]));
 }

I'm not very familiar with formatting Unicode so I don't know if there is a better approach for solving it.

Thanks!

unicode java
1 Answers

Use java.util.regex.Pattern, calling .matcher to produce a Matcher. That matcher can replace all your targeted powers by running our passed function.

private static final Pattern EXPONENT_PATTERN = Pattern.compile("\\^(\\d+)");
private static final String NORMAL_LETTERS = "0123456789";
private static final String SUPERSCRIPT_LETTERS =
    "\u2070\u00B9\u00B2\u00B3\u2074\u2075\u2076\u2077\u2078\u2079";

public static String styled(String s) {
    return EXPONENT_PATTERN.matcher(s).replaceAll(mr -> {
        char[] chs = mr.group(1).toCharArray();
        for (int i = 0; i < chs.length; ++i) {
            int j = NORMAL_LETTERS.indexOf(chs[i]);
            if (j != -1) {
                chs[i] = SUPERSCRIPT_LETTERS.charAt(j);
            }
        }
        return new String(chs);
    });
}

For letters you may search too, https://unicode-table.com/en/blocks/phonetic-extensions/ However I do not think there are many superscript math operators.

user_9848230
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