//by函数接受一个成员名字符串做为参数
//并返回一个可以用来对包含该成员的对象数组进行排序的比较函数
var by = function(name)
{
return function(o, p)
{
var a, b;
if (typeof o === "object" && typeof p === "object" && o && p)
{
a = o[name];
b = p[name];
if (a === b) {return 0;}
if (typeof a === typeof b) { return a < b ? -1 : 1;}
return typeof a < typeof b ? -1 : 1;
}
else {throw ("error"); }
}
}
var employees=[]
employees[0]={name:"George", age:32, retiredate:"March 12, 2014"}
employees[1]={name:"Edward", age:17, retiredate:"June 2, 2023"}
employees[2]={name:"Christine", age:58, retiredate:"December 20, 2036"}
employees[3]={name:"Sarah", age:62, retiredate:"April 30, 2020"}
employees.sort(by("age"));
alert(employees);

到这里，对象数组排序就算基本实现了。那如何实现多个键值排序呢？意思就是先是对age排序，如果age相同，再比较name。

这时，我们可以进一步修改by函数，让其可以接受第二个参数，当主要的键值产生一个匹配的时候，另一个compare方法将被调用以决出高下。

//by函数接受一个成员名字符串和一个可选的次要比较函数做为参数
//并返回一个可以用来包含该成员的对象数组进行排序的比较函数
//当o[age] 和 p[age] 相等时，次要比较函数被用来决出高下

var by = function(name,minor)
{
return function(o, p)
{
var a, b;
if (typeof o === "object" && typeof p === "object" && o && p)
{
a = o[name];
b = p[name];
if (a === b) {return typeof minor==='function' ?minor(o,p):0;}
if (typeof a === typeof b) { return a < b ? -1 : 1;}
return typeof a < typeof b ? -1 : 1;
}
else {throw ("error"); }
}
}
var employees=[]
employees[0]={name:"George", age:32, retiredate:"March 12, 2014"}
employees[1]={name:"Edward", age:17, retiredate:"June 2, 2023"}
employees[2]={name:"Christine", age:58, retiredate:"December 20, 2036"}
employees[3]={name:"Sarah", age:62, retiredate:"April 30, 2020"}
employees.sort(by('age',by('name')));
alert(employees);