Method isNegativeWithBrackets

src/AutoNumericHelper.js:544–546

* Return `true` if the very first character is the opening bracket, and if the rest of the `valueString` also has the closing bracket. * * @param {string} valueString * @param {string} leftBracket * @param {string} rightBracket * @returns {boolean}

(valueString, leftBracket, rightBracket)

     * @returns {boolean}
     */
    static isNegativeWithBrackets(valueString, leftBracket, rightBracket) {
        return valueString.charAt(0) === leftBracket && this.contains(valueString, rightBracket);
    }

    /**
     * Return `true` if the formatted or unformatted numeric string represent the value 0 (ie. '0,00 €'), or is empty (' €').