Google Sheets - Horizontal merge identical cells in single row

Question

I am working towards updating a sample of code seen at: Merge cells with same words Provided by @Tanaike

I am essentially trying to do the same thing as the sample c

Answer 1

If I understand correctly you want to transform a row of cells that looks like this:

Jan | Jan | Feb | Feb | Feb | Mar | Apr | Apr | Apr |

into this:

Jan | Feb | Mar | Apr |

If so, I can help!

Step 1. Getting Data

I think part of your issue comes from your call to getRange(row, column, numRows, numColumns).

In a comment you say var start = 6 is the start row, but you put it in the column spot. Not sure what you intended, but it might be more clear to have a startRow and a startCol variable. Eg,

var startRow = 1;
var startCol = 1;

// Later...
ss.getRange(startRow, startCol, 1, ss.getLastColumn())

Calling Range.getValues() in a Google Script returns a two dimensional "array-of-arrays." With the example cells I provided you would get something like:

data = [['Jan', 'Jan', 'Feb', 'Feb', 'Feb', 'Mar', 'Apr', 'Apr', 'Apr']]

Since we're just dealing with one row, we can take the first item of this outer array and call that data, simplifying things a bit. So I would do:

var data = ss
 .getRange(startRow, startCol, 1, ss.getLastColumn())
 .getValues()
 .filter(String)[0];

Which gives you:

data = ['Jan', 'Jan', 'Feb', 'Feb', 'Feb', 'Mar', 'Apr', 'Apr', 'Apr']

Step 2. Counting duplicate values

The next bit of code deals with counting how many times each month is duplicated. With our nice, one-dimensional array we can make the code a little simpler:

data.forEach(function(e) {
  c[e] = c[e] ? c[e] + 1 : 1;
});

Here we're looping over the array data, dealing with each entry "e" in turn. (e will be "Jan", then "Jan" again, then "Feb"). We're storing the counts in an object, c which starts off blank and will look like this when we're finished:

c = {Feb: 3.0, Apr: 3.0, Jan: 2.0, Mar: 1.0}

The ? and : stuff is fancy JavaScript ternary syntax, which is basically saying:

    c[e] = c[e] ? c[e] + 1 : 1;
   [-----] [-----][-------][---]
      |       |       |      |
      |       v       |      |
(1) "have we already created an entry in c for this month e (eg, "Jan")?
      |               |      |
      |               v      |
(2) "if so, COUNT is the current value (look it up) plus 1
      |                      |
      |                      v
(3)   |            "if not, COUNT is 1"
      |
      v
(4) "store the COUNT we found in c"

Step 3. Merge duplicate values

The final step could look like this:

data.forEach(function(e) {
  if (e != k) {
    ss.getRange(startRow, startCol + offset, 1, c[e]).merge();
    offset += c[e];
  }
  k = e;
});

Again, things are a tiny bit simpler because data is now a 1d array instead of a 2d array.

Complete Code

function mergeMonths() {

  var startRow = 1;
  var startCol = 1;
  var c = {};
  var k = "";
  var offset = 0;

  var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("BlockingChart1");

  // Get data from sheet
  var data = ss
  .getRange(startRow, startCol, 1, ss.getLastColumn())
  .getValues()
  .filter(String)[0];

  // Count duplicates
  data.forEach(function(e) {
    c[e] = c[e] ? c[e] + 1 : 1;
  });

  // Merge duplicate cells
  data.forEach(function(e) {
    if (e != k) {
      ss.getRange(startRow, startCol + offset, 1, c[e]).merge();
      offset += c[e];
    }
    k = e;
  });

}

Quick Tip

One final tip: The logger is super helpful for seeing what's going on in your code. When you're testing your code I would stick lines like:

Logger.log("data: %s", data);

and

Logger.log("e: %s", e);

All over the place, then check the Google Scripts log (view > logs) to understand what your variables are at different points.