* php shuffle 打乱数组顺序
Array.prototype.shuffle = function () {
"use strict";
var a = [], b = [], n = this.length, i, j, seq;
// @b: a[i] element exists?
for (i = 0; i < n; i++) {
b[i] = 0;
}
function _getIndex(b, seq) {
var n = b.length;
for (i = 0; ; i = (i+1)%n) {
if (!b[i]) {
if (seq===0) {
break;
}
seq--;
}
}
return i;
}
while (n-->0) {
seq = Math.floor(3*this.length * Math.random());
j = _getIndex(b, seq);
a.push(this[j]);
b[j] = 1;
}
return a;
};
test:
// var aa = ['DevTools', 'PHP', 'PHP_Framework', 'EclipsePDT', 'Laravel', 'PHPStorm', 'ThinkPHP5'];
var aa = [0,1,2,3,4,5,6,7,8,9];
var n = 1000;
if (typeof window === "undefined") {
while (n--) {console.log(aa.shuffle());}
} else {
while (n--) {document.write("<p>["+aa.shuffle().toString()+"]</p>");}
}
有了这个方法,以后方便测试数组排序的问题。