SOURCE

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

writeDocument("数组创建----------------------------------");
var arr=["HTML","CSS","JavaScript","jQuery","Vue.js"];

writeDocument(arr);

writeDocument("数组下标取值------------------------------");
writeDocument(arr[2]);

writeDocument("数组赋值---------------------------------");
arr[4]="React.js";
writeDocument(arr);
arr[5]="Vue.js";
writeDocument(arr);
arr[8]="Angular.js";
writeDocument(arr);
//以上是week4内容

writeDocument("获取数组的长度----------------------------");
writeDocument("数组的长度为"+arr.length);

writeDocument("获取数组的1-2号元素----------------------------");

writeDocument("往数组头添加元素----------------------------");
writeDocument("往数组尾部添加元素----------------------------");
writeDocument("删除数组的第一个元素----------------------------");
writeDocument("删除元素:"+arr.shift());

writeDocument("删除数组的最后一个元素----------------------------"); 
writeDocument("删除元素:"+arr.pop());

writeDocument("对字符串数组进行升序的排序----------------------------"); 


function upCompare(left,right){
    if(left-right>0){
        return 1;
    }
    if(left-right==0){
        return 0;
    }
    if(left-right<0){
        return -1;
    }
}

function downCompare(left, right) {
    if (left - right > 0) {
        return -1;
    }

    if (left - right == 0) {
        return 0;
    }

    if (left - right < 0) {
        return 1;
    }
} 

writeDocument("打印排序前的数字数组"+arr);
writeDocument("打印升序排列后的数组"+arr)
//以上为第一堂课内容



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

writeDocument("定义时间对象----------------------------");
var oToday=new Date();

writeDocument("获取年、月、日、时、分、秒、毫秒----------------");
writeDocument("年："+oToday.getFullYear());
writeDocument("月："+oToday.getMonth());
writeDocument("日："+oToday.getDate());
writeDocument("时："+oToday.getHours());
writeDocument("分："+oToday.getMinutes());
writeDocument("秒："+oToday.getSeconds());
writeDocument("毫秒："+oToday.getMilliseconds());

writeDocument("设置年、月、日、时、分、秒、毫秒----------------");
var oDate=new Date(2019);

oDate.setFullYear(2020);
writeDocument("年："+oToday.getFullYear());
oDate.setMonth(5);
writeDocument("月："+(oToday.getMonth()+1) );
oDate.setMonth(1);
writeDocument("日："+oToday.getDate());
oDate.setMonth(16);
writeDocument("时："+oToday.getHours());
oDate.setMonth(58);
writeDocument("分："+oToday.getMinutes());
oDate.setMonth(59);
writeDocument("秒："+oToday.getSeconds());

writeDocument("打印2019年6月1日 星期六 15:59:59:999-------------");
var oPrintDate = new Date(2019, 6, 1, 15, 59, 59, 999); 
var weeks = ["星期日", "星期一", "星期二", "星期三", "星期四", "星期五", "星期六"]; 
writeDocument("年: "+oPrintDate.getFullYear());
writeDocument("月: "+oPrintDate.getMonth());
writeDocument("日: "+oPrintDate.getDate());
writeDocument("今天是："+weeks[oPrintDate.getDate()]);
writeDocument("时: "+oPrintDate.getHours());
writeDocument("分: "+oPrintDate.getMinutes());
writeDocument("秒: "+oPrintDate.getSeconds());
writeDocument("毫秒: "+oPrintDate.getMilliseconds());


//数学对象
writeDocument("生成随机验证码----------------------");
function generateVerifyCode(length){
    var strValue ="0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ";
    var code="";
    for(var i=0;i<length;++i){
        var randomIndex=Math.floor(Math.random()*strValue.length);
        code +=strValue.charAt(randomIndex);
    }
    return code;
}

writeDocument(generateVerifyCode(4));
writeDocument(generateVerifyCode(5));
writeDocument(generateVerifyCode(6));

writeDocument("用Math的方法找出3,9,12,99,45,75中的最大值和最小值--------");
  var a = Math.max(3,9,12,99,45,75);
  var b = Math.min(3,9,12,99,45,75);
  document.write("最大值为：" + a + "<br/>");
  document.write("最小值为：" + b+ "<br/>");

writeDocument("随机生成一个颜色值rgb（x,y,z）的函数，其中x标识的是0~255--------");
function getColor() {
    var r = Math.floor(Math.random() * 256);
    var g = Math.floor(Math.random() * 256);
    var b = Math.floor(Math.random() * 256);
    var rgb = "rgb(" + r + "," + g + "," + b + ")";
    return rgb;
}
writeDocument(getColor());