SOURCE

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

writeDocument("最大值最小值---------");
writeDocument("最大值： "+Math.max(1,3,9,18,999));
writeDocument("最小值： "+Math.min(1,3,9,18,999));

writeDocument("生成4位随机验证码---------");
function generateVerifyCode(length){
    var strLetterNumber = "0123456789abcdefghijklmnopqrst*()#$~";
    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(generateVerifyCode(4));
writeDocument(generateVerifyCode(5));
writeDocument(generateVerifyCode(6));

writeDocument("生成随机的颜色，rgb(255,255,255)---------");
function getColor(){ 
            var r = Math.floor(Math.random() * (255 + 1));
            var g = Math.floor(Math.random() * (255 + 1));
            var b = Math.floor(Math.random() * (255 + 1));
            var rgb = "rgb(" + r + "," + g + "," + b + ")";
            return rgb;
        }
writeDocument(getColor());