JavaScript sort comparator function

Question

Basically I want to build a function which sorts objects in an array by one of the object\'s properties/member variables. I am preeeety sure that the comparator function is wher

Answer 1

You need to change the signature of you compare function to include the two tasks.

For ascending order (normally what you want) you need to do b < a, a < b will do descending order

//comperator function
function compareFN(a, b) {
    return b.priority < a.priority;
}

Answer 2

The comparator function returns a negative value, zero or a positive value. Those three comprise what is called here the three-way comparison. So: ''' function cmp((a, b) => { // ascending return a - b } ''' For descending return b - a

Answer 3

There are multiple problems with your comparator:

1. It refers to the global task object instead of the objects being compared.
2. It compares the object to itself.
3. It is supposed to perform a three-way comparison.

Try:

var compareFN = function(a, b) {
    return a.priority - b.priority;
}

Answer 4

The compare function needs two arguments: the first and the second element it should compare. So your compareFN should look like this:

function compareFN(taskA, taskB) {
   return taskA.priority - taskB.priority;
}

Edit: As NPE said, it is supposed to perform a three-way comparison, so a simple a < b is not so a great idea here.