Google Script sort 2D Array by any column - google-apps-script

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.

Answer 2

It seems if instead of using .getValues , you restrict to .getDataRange then perhaps your original sort code "tableData.sort([{column: 1, ascending: true}]);" can work if you avoid the square bracket.
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheets()[0];
var range = sheet.getRange("A1:C7");
// Sorts by the values in the first column (A)
range.sort(1);
// Sorts by the values in the second column (B)
range.sort(2);
// Sorts descending by column B
range.sort({column: 2, ascending: false});
I found this in Google Documentation

Answer 3

My suggestion is to use a library like underscore.js which has a lot of useful functions to manipulate collections, arrays, map/reduce, sorting etc... Works without a glitch with Google Apps Script. That's the first library I add to any project I start on GAP.