使用 TypeScript 时，如何使用定义文件定义数组中使用的类型？

Question

I am using the datatables plugin datatables.net as below:

 oTable = $('#dataTable').dataTable({ });

Here is some code that I have

$('#detailData')
    .on('click', '.sort-up', function (event) {
        event.preventDefault();
        var column = $(this).closest('th'),
            columnIndex = column.parent().children().index(column.get(0));
        oTable.fnSort([[columnIndex, 'asc']]);
        return false;
    })

This is giving me the following error with Typescript:

"Incompatible types in array literal expression"

Can anyone give me some advice on how I could fix this? It does not seem to like the fact that columnIndex is a number and 'asc' is a string. On Stack Overflow I saw the following:

var f: any[][] = [
    [Foo, [1, 2, 3]],
    [Bar, [7, 8, 9]],
];

I understand doing I need to do something like this but is there a way I can set up the definition of the fnSort function in a .d.ts file?

Answer 1

this should do the job

oTable.fnSort([<any[]>[columnIndex, 'asc']]);

arrays should be of uniform type and since you have mixed types [number, string] it throws compilation error. casting it to any[] tells compiler that every value in an array is of type 'any' (which is true btw ;) ). compiler will then generate correct js. its just a way to fool typescript compiler a bit

you can do it other way around also - convert columnIndex to string, but if you need it to be number then you have to cast array to any[]