Sort through array of n-dimensional objects in javascript

Question

I am trying to sort through arrays of n-dimensional objects based on a certain index. For example if I have an array:

var array1 = [['c',24,"John"],['a',-13,"Cindy"],['b',98,"Alex"]];

I want to be able to sort by any dimension. Does anything exist in javascript that would give me outputs that look like the following?

array1.sort(sortFunction(0));
- [['a',-13,"Cindy"],['b',98,"Alex"],['c',24,"John"]]

array1.sort(sortFunction(1));
- [['a',-13,"Cindy"],['c',24,"John"],['b',98,"Alex"]]

array1.sort(sortFunction(2));
- [['b',98,"Alex"],['a',-13,"Cindy"],['c',24,"John"]]

Thanks!

To clarify: I am aware you must write a sort function, but can you write one that takes in an argument? Here would be an example:

function sortFunction(dim){
  if (a[dim] === b[dim]) {
    return 0;
  }
  else {
    return (a[dim] < b[dim]) ? -1 : 1;
  }
}

Answer 1

You can write a function generator that take the index of the parameters in your array :

var array = [['a',24,"John"],['a',-13,"Cindy"],['b',98,"Alex"]];

  function sorting(index) {
    return function(a, b) {
        return a[index] < b[index]?-1:(a[index] > b[index])?1:0;
    }
  }

  var res1 = array.sort(sorting(0));
  var res2 = array.sort(sorting(1));
  var res3 = array.sort(sorting(2));

Answer 2

Note: this is the basic approach of how the sort callback function works. For a more elegant solution see Paul Boute's answer . His solution is especially useful when the function needs to be applied in more than one situation.

---

Your sort function needs to compare two properties of the elements (or the two elements) themselves. It needs to return a negative number if they are in the correct order, 0 if they are equivalent and a positive number if they are in the wrong order.

A JavaScript example of such a function:

function sortFunction(elementA,elementB,index){
  if(elementA[index]<elementB[index]){
    return -1;
  }
  else if(elementA[index]>elementB[index]){
    return 1;
  }
  else{
    return 0;
  }
}

Invokable as such:

array1.sort(function(a,b){
  return sortFunction(a,b,1);
});

---

Or the shorter all-in-one version:

array1.sort(function(a,b){
  var index=1;
  if(a[index]<b[index]){
    return -1;
  }
  else if(a[index]>b[index]){
    return 1;
  }
  else{
    return 0;
  }
});

Answer 3

You can also use a library like underscore.js . Then, simply

// which index to sort on
var s = 1;
// sort it - it will work for objects too
_.sortBy(array1, function(a){ return a[s];});

// or simply use "property name" to sort on
_.sortBy( array1, s);