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(1,3,9,10,18,999));

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 rgb(){
    var r =Math.floor(Math.random()*256);
    var g =Math.floor(Math.random()*256);
    var b =Math.floor(Math.random()*256);

    writeDocument("三种随机生成颜色为：rgb("+r+","+g+","+b+")");
}

rgb();