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);

//超过之前的数组是不会报错
writeDocument("数组添加-----------------------------------------------");
arr[5]="Vue.js"
writeDocument(arr);

arr[8]="Angular.js"
writeDocument(arr);

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

writeDocument("获取数组的某一段----------------------------------------------");
writeDocument("数组1-2的元素是："+arr.slice(1,3));

writeDocument("往数组头添加元素----------------------------------------------");
writeDocument(arr.unshift("Web","Technology"));
writeDocument(arr);

writeDocument("往数组尾添加元素----------------------------------------------");
writeDocument(arr.push("Bootstrap","Sass"));
writeDocument(arr);

writeDocument("删除数组中的第一个元素----------------------------------------------");
writeDocument("删除元素"+arr.shift());
writeDocument(arr);

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

writeDocument("对字符串按升序排序----------------------------------------------");
writeDocument(arr.sort());

var numArr=[3,6,9,11,1,4];
writeDocument("排序前"+numArr);

//定义升序函数
function upcompare(l,r){
    if(l>r){
        return 1;
    }
    if(l==r){
        return 0;
    }
    if(l<r){
        return -1;
    }
}
numArr.sort(upcompare);
writeDocument("升序后"+numArr);

//定义降序函数
function downcompare(l,r){
    if(l>r){
        return -1;
    }
    if(l==r){
        return 0;
    }
    if(l<r){
        return 1;
    }
}
numArr.sort(downcompare);
writeDocument("降序后"+numArr);

writeDocument("反转数组:"+numArr.reverse());
writeDocument("默认Join数组:"+numArr.join());
writeDocument("默认Join数组:"+numArr.join(":"));
writeDocument("默认Join数组:"+numArr.join("-"));
writeDocument("默认Join数组:"+numArr.join("><"));

//数组与字符串的转换操作
function addAngleBracket(strVaule){
    var strArr=strVaule.split("");
    console.log(strArr);
    var str=strArr.join("><");
    console.log(str);
    strArr=str.split("");
    console.log(strArr);
    strArr.unshift("<");
    strArr.push(">");
    console.log(strArr);
    return strArr.join("");
}
writeDocument(addAngleBracket("绿叶学习网"));

//计算面积与体积，返回一个数组
function getSize(width,height,depth){
    var area=width*height;
    var volume=width*height*depth;
    var sizes = [area, volume];
    return sizes;
}
var arr=getSize(10,20,30);
writeDocument("底部面积为：" + arr[0]);
writeDocument("体积为：" + arr[1] + "<br/>");