Circled Number 0 to 20 & html escape unicode code.

circledNumberHTMLCode.js

// ⓪ ⓪ Circled Digit Zero
// ① ① Circled Digit One
// ② ② Circled Digit Two
// ③ ③ Circled Digit Three
// ④ ④ Circled Digit Four
// ⑤ ⑤ Circled Digit Five
// ⑥ ⑥ Circled Digit Six
// ⑦ ⑦ Circled Digit Seven
// ⑧ ⑧ Circled Digit Eight
// ⑨ ⑨ Circled Digit Nine
// ⑩ ⑩ Circled Number Ten
// ⑪ ⑪ Circled Number Eleven
// ⑫ ⑫ Circled Number Twelve
// ⑬ ⑬ Circled Number Thirteen
// ⑭ ⑭ Circled Number Fourteen
// ⑮ ⑮ Circled Number Fifteen
// ⑯ ⑯ Circled Number Sixteen
// ⑰ ⑰ Circled Number Seventeen
// ⑱ ⑱ Circled Number Eighteen
// ⑲ ⑲ Circled Number Nineteen
// ⑳ ⑳ Circled Number Twenty
function zeroToTwentyAsCircledNumberUnicodeHTMLCode(n) {
    if (n === 0) {
        return '&#9450';
    } else if (n > 20 || n < 0) {
        return '?';
    }
    return '&#'+(9311 + n);
}