Question

I’m trying to sort an array of objects. I’d prefer not to write a custom sort method for each attribute.

Is there anyway I could extend the built-in array.sort() method to accept an extra parameter, describing the attribute to sort on? E.g.,

array.sort(function(a, b, attr) { return a.attr - b.attr; }, 'name');

Answer 1

Write a function generator that accepts a property name:

function propComparator(prop) {
    return function(a, b) {
        return a[prop] - b[prop];
    }
}

arr.sort(propComparator('name'));

You can also save the sorters for later use, directly, or as parameters:

var compareNames = propComparator('name');
var compareFoos = propComparator('foo');
...
arr.sort(compareNames);
takesComparator(compareFoos);

---

sort sorts in-place, which may or may not be desirable.

---

(Updated for ES6, and so it actually works with different types.)

const arr = [
  { name: 'John', age: 92 },
  { name: 'Dave', age: 42 },
  { name: 'Justin', age: 3 }
]

const propComparator = (propName) =>
  (a, b) => a[propName] == b[propName] ? 0 : a[propName] < b[propName] ? -1 : 1

arr.sort(propComparator('name'))
console.log("By name", arr)

arr.sort(propComparator('age'))
console.log("By age", arr)