quoteString

quoteString.js

/**
 * quote function
 * @see {@link https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/quote|MDN}
 * @param {string} str
 * @param {string} quote
 * @returns {string} quote a string
 */
function quoteString(str, quote) {
    str = "" + str;
    quote = "" + (quote || "\"");

    var meta = {
        "\b": "\\b",
        "\t": "\\t",
        "\n": "\\n",
        "\v": "\\v",
        "\f": "\\f",
        "\r": "\\r",
        "\\": "\\\\"
    };
    meta[quote] = "\\" + quote;

    var hexDigits = "0123456789ABCDEF".split("");

    var newStr = "";
    newStr += quote;

    var i, len, ch, cc;
    for (i = 0, len = str.length; i < len; i++) {
        ch = str[i];
        if (meta.hasOwnProperty(ch)) {
            newStr += meta[ch];
            continue;
        }
        cc = ch.charCodeAt(0);
        if (cc >> 8) {
            newStr += "\\u" + hexDigits[(cc >> 12) & 0xF] + hexDigits[(cc >> 8) & 0xF] + hexDigits[(cc >> 4) & 0xF] + hexDigits[cc & 0xF]; // or "\\u" + ("0000" + cc.toString(16).toUpperCase()).slice(-4)
        } else {
            if (cc > 0x1F && cc < 0x7F) {
                newStr += ch;
            } else {
                newStr += "\\x" + hexDigits[(cc >> 4) & 0xF] + hexDigits[cc & 0xF]; // or "\\x" + ("00" + cc.toString(16).toUpperCase()).slice(-2)
            }
        }
    }

    newStr += quote;

    return newStr;
}