数组方法

//去重1

var arr = [1, 2, 3, 4, 5, 5, 4, 6, 78, 1, 789, 8975, 78]; var ar = []; for(var i in arr) { if(ar.indexOf(arr[i]) == -1) { ar.push(arr[i]); } } document.write("去重:" + ar + "
");

document.write("------------------------------" + "
")

//去重2

function qucong(arr) { for(var i = 0; i < arr.length; i++)

{ for(var j = i + 1; j < arr.length; j++) { if(arr[i] == arr[j]) { arr.splice(j, 1); //j--; } } } return arr; }

document.write("去重:" + qucong([2, 2, 2, 3, 1]) + "
"); document.write("------------------------------" + "
")

//排序 var arr = [3, 2, 4, 7, 4, 8, 2, 1];

function fn(a, b) { return a - b; }

var aa = arr.sort() document.write("排序:" + aa.join("<") + "
")

document.write("------------------------------" + "
")

//数组排序

var arr = [3, 31, 11, 6, 9, -11]; for(var j = 0; j < arr.length - 1; j++) { //外层循环排5次

for(var i = 0; i < arr.length; i++) {//每次排序得到最后一个值

if(arr[i] >= arr[i + 1]) { //判断相邻两数的大小

var tempArr = arr[i + 1]; //做一个临时变量=第二个数

arr[i + 1] = arr[i]; //将第一个数换到第二个位置

arr[i] = tempArr; //再将装到临时变量的第二个数放到第一个位置

} } }

document.write("数组排序:" + arr + "

"); document.write("------------------------------" + "
")

//去重加排序

var arr = [1, 2, 3, 4, 5, 5, 4, 6, 78, 1, 789, 8975, 78];

var ar = []; for(var i in arr) { if(ar.indexOf(arr[i]) == -1) { ar.push(arr[i]); } }

document.write("去重加排序:" + ar.sort(fn).join("<") + "
")

function fn(a, b) { return a - b; } document.write("------------------------------" + "
")

//阶乘

function jc(num) { if(num == 1) { return 1; } else { return num * jc(num - 1); } }

document.write("阶乘：" + jc(5) + "
");

document.write("------------------------------" + "
")

//水仙花

function sxh() { for(var i = 100; i < 1000; i++) { var bai = parseInt(i / 100); var shi = parseInt(i % 100 / 10);

var ge = parseInt(i % 100 % 10); if(i == bai * bai * bai + shi * shi * shi + ge * ge * ge) { document.write("水仙花：" + i + "
");

} } }

sxh(); document.write("------------------------------" + "
")

//各个位置相加

function kk(num) { var bai = parseInt(num / 100);

var shi = parseInt(num % 100 / 10);

var ge = parseInt(num % 100 % 10);

document.write(bai + shi + ge); } kk(135); document.write("
" + "------------------------------" + "
")

//100以内能够被3整除的所有数  按一行6个进行排列

function hu() { var index = 0;

for(var k = 1; k <= 100; k++) { if(k % 3 == 0) { document.write(k + " "); index++; }

if(index == 6) { document.write("
"); index = 0;

} } }

hu();

document.write("
" + "------------------------------" + "
") //单词首字母大写 var arr = "welcome to rong er"; function szmdx(s) { var i, ss = s.toLowerCase().split(/\s+/); for(var i = 0; i < ss.length; i++) { ss[i] = ss[i].slice(0, 1).toUpperCase() + ss[i].slice(1); } return ss.join(' '); } document.write(szmdx(arr));