[SOLVED] Typescript sort array of array tuples

Typescript sort array of array tuples

I have tuples in the form (Status and priority)

[State,prio]

States are defined so:

enum State {
    A = "A",
    B = "B",
    C = "C"
   ...
}

Now i want to sort an array of State tuples by priority using the sort function:

compareFn(a:[State,number], b:[State,number]):number {
     if (a[1] > b[1]) {
         return -1;
     } else if (a[1] < b[1]) {
         return 1;
     }
     return 0;
}

This is the array:

let prio =  [
   [State.A, 23], 
   [State.B, 2],
   [State.C, 5]
]

When invoking the array sort function with the compareFn callback

prio.sort(compareFn)

the following error is given:

Argument of type '(a: [State, number], b: [State, number]) => number' is not assignable to parameter of type '(a: (number | State)[], b: (number | State)[]) => number'. Types of parameters 'a' and 'a' are incompatible. Type '(number | State)[]' is not assignable to type '[State, number]'.

I have no idea where this data type comes from and how to resolve this:

(number | State)[]

Any ideas?

Solution

Answer by @nseaprotector is correct. You could also inline the compare directly if you prefer, see below:

enum State {
  A = "A",
  B = "B",
  C = "C"
}

const prio: [State, number][] = [
  [State.A, 23],
  [State.B, 2],
  [State.C, 5]
];

prio.sort((a, b) => b[1] - a[1]);
console.log(prio);