Sorting an array of JavaScript objects

I read the following objects using Ajax and stored them in an array:

var homes = [
    {
        "h_id": "3",
        "city": "Dallas",
        "state": "TX",
        "zip": "75201",
        "price": "162500"
    }, {
        "h_id": "4",
        "city": "Bevery Hills",
        "state": "CA",
        "zip": "90210",
        "price": "319250"
    }, {
        "h_id": "5",
        "city": "New York",
        "state": "NY",
        "zip": "00010",
        "price": "962500"
    }
];

How do I create a function to sort the objects by the price property in ascending or descending order using only JavaScript?

---

Sort homes by price in ascending order:

homes.sort(function(a, b) {
    return parseFloat(a.price) - parseFloat(b.price);
});

Or after ES6 version:

homes.sort((a, b) => parseFloat(a.price) - parseFloat(b.price));

Some documentation can be found here.

---

Here's a more flexible version, which allows you to create reusable sort functions, and sort by any field.

var sort_by = function(field, reverse, primer){

   var key = primer ? 
       function(x) {return primer(x[field])} : 
       function(x) {return x[field]};

   reverse = !reverse ? 1 : -1;

   return function (a, b) {
       return a = key(a), b = key(b), reverse * ((a > b) - (b > a));
     } 
}

Now you can sort by any field at will...

var homes = [{

   "h_id": "3",
   "city": "Dallas",
   "state": "TX",
   "zip": "75201",
   "price": "162500"

}, {

   "h_id": "4",
   "city": "Bevery Hills",
   "state": "CA",
   "zip": "90210",
   "price": "319250"

}, {

   "h_id": "5",
   "city": "New York",
   "state": "NY",
   "zip": "00010",
   "price": "962500"

}];

// Sort by price high to low
homes.sort(sort_by('price', true, parseInt));

// Sort by city, case-insensitive, A-Z
homes.sort(sort_by('city', false, function(a){return a.toUpperCase()}));

---

To sort it you need to create a comparator function taking two arguments. Then call the sort function with that comparator function as follows:

// a and b are object elements of your array
function mycomparator(a,b) {
  return parseInt(a.price, 10) - parseInt(b.price, 10);
}
homes.sort(mycomparator);

If you want to sort ascending switch the expressions on each side of the minus sign.

链接地址: http://www.djcxy.com/p/3236.html

上一篇: 公共，私人和受保护之间有什么区别？

下一篇: 排序一组JavaScript对象