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[4]);
//增加
arr[5]="Vue.js";

writeDocument(arr);

arr[8]="Augular.Js";

writeDocument(arr);

writeDocument("获取数组长度------------------------")
//数组名.length
var arr=["abc","cde","fij"];
writeDocument(arr);
writeDocument(arr.length);

writeDocument("截取数组某部分------------------------")
//数组名.slice[start,end)
writeDocument(arr.slice(0,2));

writeDocument("往数组头添加元素------------------------")
// 数组名.unshift
writeDocument(arr.unshift("jkl","mno"));
writeDocument(arr);

writeDocument("往数组尾添加元素------------------------")
// 数组名.push
writeDocument(arr.push("xyz","cvb"));
writeDocument(arr);

writeDocument("删除数组第一个元素------------------------")
// 数组名.shift
writeDocument(arr.shift());
writeDocument(arr);

writeDocument("删除数组最后一个元素------------------------")
// 数组名.pop
writeDocument(arr.pop());
writeDocument(arr);

writeDocument("对字符串数组按升序排序------------------------")
//数组名.sort(函数名):元素进行大小比较
writeDocument(arr.sort());

var numArr=[3,6,9,1,4,11];

writeDocument(numArr);
function compare(a,b){
    if(a>b)
    {
        return 1;
    }
    if(a==b)
    {
        return 0;
    }
    if(a<b)
    {
        return -1;
    }
}
numArr.sort(compare) //不调用,当变量用,就不加括号 
writeDocument("升序排序后:"+numArr);

function downcompare(a,b){
    if(a>b)
    {
        return -1;
    }
    if(a==b)
    {
        return 0;
    }
    if(a<b)
    {
        return 1;
    }
}
numArr.sort(downcompare)
writeDocument("降序排序后:"+numArr);

writeDocument("对数组反向排序------------------------")
//数组名.re
writeDocument(numArr.reverse());

writeDocument("将数组元素连接成字符串------------------------")
//数组名.join("连接符")
writeDocument(numArr.join("-"));

writeDocument("数组与字符串的转换操作------------------------")

var str1 = "绿叶学习网";
var str2 = str1.split("").join("><");
var arr = str2.split("");
arr.unshift("<");
arr.push(">");
var result = arr.join("");
document.write(result+'<br/>');

writeDocument("------------------------")


//设计一个函数,计算一个长方体的底部面积和体积,最终返回底部面积和体积的结果。
//length,width,height
function getarea(l,w,h)
{
    var bottomarea=w*l;
    var volumn=w*h*l;
    var sizes=[bottomarea,volumn];
    return sizes;
}

var str = getarea(5,10,7);
writeDocument("底部面积为:"+str[0]);
writeDocument("体积为:"+str[1]);

var arr=[1,2,3,4,5];
var sum=0;
for(var i=1;i<arr.length;i++){
    sum+=arr[i];

}
writeDocument(sum);
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