JavaScriptでcheckdate()

JavaScriptでPHPのcheckdate()相当の関数を実装

function checkdate(month, day, year) {

    if (isNaN(month) || isNaN(day) || isNaN(year)) return false;

    if (month <= 0 || day <= 0 || year <= 0) return false;

    var dd = new Date(year, month - 1, day);

    if (year != dd.getFullYear() || month != dd.getMonth() + 1 || day != dd.getDate()) return false;

    return true;

}