Javascript – Sort an array in the same order of another array

comparejavascriptsorting

I have a few arrays of 50+ names like this.

["dan", "ryan", "bob", "steven", "corbin"]
["bob", "dan", "steven", "corbin"]

I have another array that has the correct order. Note that the second array above does not include all of the names, but I still want it to follow the order of the following:

["ryan", "corbin", "dan", "steven", "bob"]

There is no logical order to it, they are just in this order. What makes sense to me is to compare each array against the correctly ordered one. I think I saw some people doing this with PHP, but I was not able to find a JavaScript solution. Does anyone have any idea how to do this? I've been trying for a few hours and I'm stumped.

Best Solution

Use indexOf() to get the position of each element in the reference array, and use that in your comparison function.

var reference_array = ["ryan", "corbin", "dan", "steven", "bob"];
var array = ["bob", "dan", "steven", "corbin"];
array.sort(function(a, b) {
  return reference_array.indexOf(a) - reference_array.indexOf(b);
});
console.log(array); // ["corbin", "dan", "steven", "bob"]

Searching the reference array every time will be inefficient for large arrays. If this is a problem, you can convert it into an object that maps names to positions:

var reference_array = ["ryan", "corbin", "dan", "steven", "bob"];
reference_object = {};
for (var i = 0; i < reference_array.length; i++) {
    reference_object[reference_array[i]] = i;
}
var array = ["bob", "dan", "steven", "corbin"];
array.sort(function(a, b) {
  return reference_object[a] - reference_object[b];
});
console.log(array);