<html><head> <title>js两个数组排列组合</title> <script type="text/javascript"> var a = ["A","B","C"] var b = ["1", "2","3"] window.onload = function () {var a1 = new objPL(a)//计算数组a的排列组合var b1 = new objPL(b)//计算数组b的排列组合var str = "" var n = 0 //a1和b1的排列组合个数就是两者相乘（双层循环）for (var i = 0i <a1.lengthi++) {for (var j = 0j <b1.lengthj++) {str += a1[i] + b1[j] + " " n++ }str += "<br/>" }document.write("共" + n + "个<br/>") document.write(str) }//取数组的排列组合function objPL(arr) {this.a = arr this.r = [] this.n = 0 //从M个数里面取N个(递归)this.mGetN = function (curIndex, num, curSelect) {if (num == 0) {this.r[this.n++] = curSelectreturn }if (this.a.length - curIndex <num) return this.mGetN(curIndex + 1, num - 1, curSelect + this.a[curIndex]) this.mGetN(curIndex + 1, num, curSelect) }for (var i = 1i <= this.a.lengthi++) {this.mGetN(0, i, "") }return this.r }</script></head><body></body></html>
["A","B","C"]与["1","2","3"]组合的结果：
数组排序，你可以直接调用javascript原生自带的sort()方法，比如下面的例子：
// Array.prototype.sort() //原生自带的数组的排序方法；
var fruit = ['apples', 'bananas', 'Cherries'] //定义一个数组
fruit.sort()// ['Cherries', 'apples', 'bananas'] //按字母排序的结果
var scores = [1, 2, 10, 21] //定义一个数字排序，你发现其实还是按照字母序排列的
scores.sort()// [1, 10, 2, 21]
如果希望按照期望的数字排序。
scores.sort(function(a,b){return a-b})//这样的就可以了。结果为：21 10 2 1
var things = ['word', 'Word', '1 Word', '2 Words']
things.sort()// ['1 Word', '2 Words', 'Word', 'word']
// In Unicode, numbers come before upper case letters,
// which come before lower case letters.
