Google Script sort 2D Array by any column

Question

I had a asked an earlier question about retrieving records from a database, here: Retrieving Records from a Google Sheet with Google Script

I'm fairly comfortable with manipulating arrays and creating my own sorting algorithms, but I want to use the existing Array.sort() method to organize the data because of its speed. I'm finding that I can easily use this to sort a 2D array by the first column of data, but I can't find the syntax to sort on a different column of data, other than the first.

The closest that I've found is this: Google Apps Script Additional Sorting Rules. However, these inputs haven't worked for me. Here is what I get for the following code, for my array, tableData:

tableData.sort([{ column: 1}]);

=>TypeError: (class)@4dde8e64 is not a function, it is object. (line 49, file "sortTablebyCol")

tableData.sort([{column: 1, ascending: true}]);

=> TypeError: (class)@4d89c26e is not a function, it is object. (line 50, file "sortTablebyCol")

What is the proper syntax for choosing which column of data to sort on?

Answer 1

The array.sort method can have a function argument to choose on what part you want to sort. Code goes like this :

    array.sort(function(x,y){
      var xp = x[3];
      var yp = y[3];
// in this example I used the 4th column... 
      return xp == yp ? 0 : xp < yp ? -1 : 1;
    });

---

EDIT

Following your comment, here is a small demo function that should help to understand how this works.

Instead of using short form if/else condition I used the traditional form and splitted it in 3 lines to make it easier to understand.

function demo(){
  // using a full sheet as array source
  var array = SpreadsheetApp.getActive().getActiveSheet().getDataRange().getValues();
  Logger.log('Unsorted array = '+array);
  array.sort(function(x,y){
// in this example I used the 4th column... 
    var compareArgumentA = x[3];
    var compareArgumentB = y[3];
    // eventually do something with these 2 variables, for example Number(x[0]) and Number(y[0]) would do the comparison on numeric values of first column in the array (index0) 
    // another example x[0].toLowerCase() and y[0].toLowerCase() would do the comparison without taking care of letterCase...
    Logger.log('compareArgumentA = '+compareArgumentA+' and compareArgumentB = '+compareArgumentB);
    var result = 0;// initialize return value and then do the comparison : 3 cases
    if(compareArgumentA == compareArgumentB ){return result }; // if equal return 0
    if(compareArgumentA < compareArgumentB ){result = -1 ; return result }; // if A<B return -1 (you can change this of course and invert the sort order)
    if(compareArgumentA > compareArgumentB ){result = 1 ; return result }; // if a>B return 1
    }
            );
  Logger.log('\n\n\nSorted array = '+array);
}

I added a couple of Logger.log to check starting, intermediate and final values. Try this in a spreadsheet.

Hoping this will help.