SOURCE

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

writeDocument("最大值最小值---------------------");
writeDocument("最大值"+Math.max(1,3,9,10,18,999));
writeDocument("最小值"+Math.min(1,3,9,10,19,999));

writeDocument("生成4位随机验证码---------------------")
function generateVerifyCode(length){
    var strLetterNumber="0123456789ABCDEFGHIGKLMNOPQRSTUVWXYZ";
    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("生成随机颜色 rgb(255,255,255)------------------")
function getRandomColor() {
    var red = Math.floor(Math.random() * (255 + 1));
    var green = Math.floor(Math.random() * (255 + 1));
    var blue = Math.floor(Math.random() * (255 + 1));
    writeDocument( "rgb(" + red + "," + green + "," + blue + ")");
}
getRandomColor();