Question

I used to have an array of arrays and used a sort function to get the proper order like:

var sampleArr = [
  [272, 'Some Title', 1, 1],
  [281, 'Some Other Title', 1, 2],
  [287, 'Another Title', 2, 1]
];

sampleArr.sort(sortCourses);

function sortCourses(a, b){
  if (a[3] == b[3]) {
    return (a[2] - b[2]);
  } else {
    return (a[3] - b[3]);
  }
}

That is the desired result, however we have changed to have the id as a property and the value of the property an array like:

var sampleObj = {
  272: ['Some Title', 1, 1],
  281: ['Some Other Title', 1, 2],
  287: ['Some Other Title 2', 2, 1]
};  

This makes our life a lot easier with lookups for that id, however I am not sure how to sort it.

Can anyone shed some light on the best way to accomplish this? Do I need to convert it back to an array with a function and then run the same sort function? If so, how would I convert the sampleObj back to the original format?

Thanks.

Answer 1

I would simply convert it back to the original format. This is easy:

var array = Object.keys(sampleObj).map(function(key) {
  return [Number(key)].concat(sampleObj[key])
})

Object.keys() is an ECMAScript 5 function, so this code won’t work in IE6-8, but it will in basically every other browser.