javascript - Convert numbers to letters beyond the 26 character alphabet

Question

I'm creating some client side functions for a mappable spreadsheet export feature.

I'm using jQuery to manage the sort order of the columns, but each column is ordered like an Excel spreadsheet i.e. a b c d e......x y z aa ab ac ad etc etc

How can I generate a number as a letter? Should I define a fixed array of values? Or is there a dynamic way to generate this?

Answer 1

I think you're looking for something like this

    function colName(n) {
        var ordA = 'a'.charCodeAt(0);
        var ordZ = 'z'.charCodeAt(0);
        var len = ordZ - ordA + 1;
      
        var s = "";
        while(n >= 0) {
            s = String.fromCharCode(n % len + ordA) + s;
            n = Math.floor(n / len) - 1;
        }
        return s;
    }

// Example:

    for(n = 0; n < 125; n++)
            document.write(n + ":" + colName(n) + "<br>");