SOURCE

function writeDocument(variable){
    document.write(variable + "<br/>")
}

// 创建时间对象---------------------------------------------------------
var otime =new Date();
//获取年月日------------------------------------------------------------
writeDocument("今天是" + otime.getFullYear() + "年"
                + (otime.getMonth() + 1)+ "月"
                + otime.getDate()+ "日");
// 获取时分秒------------------------------------------------------------
writeDocument("现在是" + otime.getHours() + "时"
                + otime.getMinutes() + "分"
                + otime.getSeconds()+ "秒");

writeDocument( "------设置时间为2019年6月1日 星期六 15：59：59：99---------");
var haveTime =new Date();
haveTime.setFullYear(2019);
haveTime.setMonth(06);
haveTime.setDate(01);
haveTime.setHours(15);
haveTime.setMinutes(59);
haveTime.setSeconds(59,99);
var week=["日","一","二","三","四","五","六"];
writeDocument(  haveTime.getFullYear() + "年"
                + (haveTime.getMonth() + 1)+ "月"
                + haveTime.getDate()+ "日"
                + " "
                + "星期" + week[6]
                + " "
                + haveTime.getHours() + ":"
                + haveTime.getMinutes() + ":"
                + haveTime.getSeconds());

// 数字对象---------------------------------------------------------
writeDocument("<br/>" + "最大值最小值--------------------")
writeDocument("最大值：" + Math.max(9,5,3,99,15,2));
writeDocument("最小值：" + Math.min(9,5,3,99,15,2));

// 生成随机码--------------------------------------------------------
function generateVerifyCode(length){
    var strLetterNumber = "0123456789ABCDEFGHIJKLMNOBQRSTU";
    var code = "";
    for(var i = 0 ; i < length ; i++){
        var randomNumber = Math.floor(Math.random() * strLetterNumber.length);
        code = code + strLetterNumber.charAt(randomNumber);
    }
    return code;
}
writeDocument("<br/>" + "随机码：" + generateVerifyCode(4));
writeDocument("随机码：" + generateVerifyCode(5));
writeDocument("随机码：" + generateVerifyCode(6));

// 生成随机颜色-----------------------------------------------------
writeDocument("<br/>" + "生成随机颜色rgb(255,255,255)------------------------");
function generateRandomColor(){
    var red = Math.floor(Math.random() * 256);
    var green = Math.floor(Math.random() * 256);
    var blue = Math.floor(Math.random() * 256);
    writeDocument("rgb(" + red + "," + green + "," + blue + ")");
}
generateRandomColor();