Sorting an Array of JavaScript Objects a Specific Order (using existing function)

Question

Given an array of objects:

 {     key: "a",     value: 42 }, {     key: "d",     value: 28 }, {     key: "c",     value: 92 }, {     key: "b",     value: 87 } 

and an array of keys:

["c", "a", "b", "d"] 

Is there a ECMAScript function or a 3rd-party JavaScript library that lets you sort - in one line/function call - the first array of objects, to match the order of the keys specified in the second array, such that the result is:

 {     key: "c",     value: 92 }, {     key: "a",     value: 42 }, {     key: "b",     value: 87 }, {     key: "d",     value: 28 } 

Other questions that provide a function or algorithm:

• Javascript - sort array based on another array - Stack Overflow
• javascript - How do I sort an array of objects based on the ordering of another array? - Stack Overflow

Similar/related questions:

• Sorting an Array of Objects in PHP In a Specific Order
• php - Sort array of objects

Answer 1

Just use indexOf to convert the key to the correct order:

var order = ["c", "a", "b", "d"]; _.sortBy(arr, function(obj){      return _.indexOf(order, obj.key); }); 

Fiddle

If there are a lot of keys, then it would be advantageous to make a hash-map out of the array, like:

var order = ["c", "a", "b", "d"]; var orderMap = {}; _.each(order, function(i) { orderMap[i] = _.indexOf(order, i); }); 

This makes the key-sorting lookup constant time rather than O(n). (Fiddle)