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);

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

writeDocument("获取数组的1-2号元素----------------------------");
writeDocument("获取数组的1-2号元素"+arr.slice(1,3));
writeDocument(arr);
writeDocument(" ");

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

writeDocument("往数组尾部添加元素----------------------------");
writeDocument("往数组尾添加元素"+arr.push("C++","C#"));
writeDocument(arr);
writeDocument(" ");

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

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

writeDocument("对字符串数组进行升序的排序----------------------------");
writeDocument("升序排序："+arr.sort());
writeDocument(" ");


//compareFunction(a, b) 小于 0 ，那么 a 会被排列到 b 之前.
//compareFunction(a, b) 等于 0 ， a 和 b 的相对位置不变。
//compareFunction(a, b) 大于 0 ， b 会被排列到 a 之前。 
var numArr = [3,5,9,22,66,6];

writeDocument("sort----------------------------");
writeDocument(numArr.sort());

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

writeDocument("打印排序的数字数组"+numArr);
writeDocument("打印升序排列后的数字数组"+numArr.sort(upCompare));
writeDocument("打印降序排列后的数字数组"+numArr.sort(downCompare));

writeDocument("反转数组----------------------------");

writeDocument(numArr.reverse());

writeDocument(numArr.join(";"));

writeDocument(numArr.join("<"));


writeDocument("给字符添加尖括号----------------------------");
function addAngleBracket(strValue){
    return " ";
}
var strValue = "绿叶学习网";
writeDocument(strValue);
writeDocument(addAngleBracket(strValue)); 

writeDocument("")