SOURCE

function writeDocument(variable){
    document.write(variable+"</br>");
}
//数组的赋值
writeDocument("数组创建---------------------");
var arr = ["HTML","CSS","JavaScript","jQuery","Vue.js"]; 

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

writeDocument("数组赋值---------------------");
arr[4]="React.js";
writeDocument(arr);

arr[5]="Vue.js";
writeDocument(arr);

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

//获取数组长度
writeDocument("获取数组长度---------------------");
writeDocument(arr.length+"</br>");

writeDocument("获取数组某一段---------------------");
writeDocument(arr.slice(2, 4)+"</br>");

writeDocument("往数组头添加元素---------------------");
writeDocument(arr.unshift("C++", "Phthon"));
writeDocument(arr+"</br>");

writeDocument("往数组尾添加元素---------------------");
writeDocument(arr.push("C++", "Phthon"));
writeDocument(arr+"</br>");

writeDocument("删除数组第一个元素---------------------");
writeDocument(arr.shift());
writeDocument(arr+"</br>");

writeDocument("删除数组最后一个元素---------------------");
writeDocument(arr.pop());
writeDocument(arr+"</br>");

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

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

function upcompare(a,b){
    if(a>b){
        return 1;
    }
    if(a==b){
        return 0;
    }
    if(a<b){
        return -1;
    }
}
numArr.sort(upcompare);
writeDocument("升序排列后："+numArr+"</br>");

writeDocument("对字符串数组按降序排列---------------------");
writeDocument(arr.sort());

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

function downcompare(l,r){
    if(l>r){
        return -1;
    }
    if(l==r){
        return 0;
    }
    if(l<r){
        return 1;
    }
}
numArr.sort(downcompare);
writeDocument("降序排列后："+numArr);

writeDocument("颠倒数组排序---------------------");
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("><"));


var m = "绿叶学习网";
var i = m.split("").join("><");
var arr = i.split("");
arr.unshift("<");//在数组头部添加符号“<”
arr.push(">");//在数组尾部添加符号“>”

writeDocument("数组与字符串的转换："+arr.join(""));