SOURCE

function writeDocument(variable) {
    document.write(variable + "<br/>");
} 
var arr = ["HTML","CSS","JavaScript","jQuery","Vue.js"]; 
writeDocument("数组的创建---------")
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);
var t=["i","am","happy","now"];
writeDocument("获取数组长度--------");
writeDocument(t.length);
writeDocument("获取数组某一段");
writeDocument(t.splice(0,3));
writeDocument("往数组头添加元素");
writeDocument(t.unshift("web"));
writeDocument("往数组尾部添加元素");
writeDocument(t.push("12"));
writeDocument("往数组头删除元素");
writeDocument(t.shift());
writeDocument("往数组尾部删除元素");
writeDocument(t.pop());
writeDocument(t);

writeDocument("对字符串数组按升序排序");
writeDocument("往数组尾部删除元素");
var numarr=[3,6,9,1,4,11];
function compare(a,b){
    if(a>b){
        return 1
    }
    if(a==b){
        return 0;
    }
    if(a<b){
        return -1;
    }
}
numarr.sort(compare);
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("降序序排序后"+numarr);

writeDocument("翻转数组"+numarr.reverse());

writeDocument("默认join"+numarr.join());

writeDocument("默认join"+numarr.join(";"));

var string=["绿叶学习网"];
function add(strValue){var strArr=strValue.split("");
console.log(str);
strArr=str.split("");
console.log(strArr);
strArr.unshift("<");
strArr.push(">");
console.log(strArr);
return strArr.join()
}
var stringa=string.split("");
writeDocument(string.sp().join("<>"));
writeDocument(string.splice(1));