Count cell values only if another condition is met

I currently use the below function to count the occurances of the same value in a column.

function countRecords() {

  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  
  const last = sheet.getLastRow();
  const range = 'B1:A' + last ;
  const data = sheet.getRange(range).getValues();
  
  const counts = {};

  data.forEach(function (x) { counts[x] = (counts[x] || 0) + 1; });
  var result = Object.entries(counts);
  return result; 
  
}

This results in an array with each unique value and a count of how many times it appears in the column. I now have a requirement to only count the value if another value in column k on the row exists.

For Example

I would expect the output to be [Val1, 2][Val2, 1], it should only count the rows where COLK is empty.

I have tried nesting loops but I am getting more confused as I go and would appreciate some help.

You may try this code:

function countRecords() {
  var sheet = SpreadsheetApp.getActiveSpreadsheet().getActiveSheet();
  var lr = sheet.getLastRow();
  var lc = sheet.getLastColumn();
  var data = sheet.getRange(1, 2, lr, lc - 1).getValues(); // If column K is the last column, use lc-1. Otherwise, manually change it to 10.
  var fitleredData = data.map(x=>[x[0],x[x.length-1]]); 
  var colA = fitleredData.filter(x => x[1] == "").flat().filter(x => x != "");
  var newColA = Array.from(new Set(colA));
  var count = newColA.map(x => colA.filter(y => y == x).length);
  var out = newColA.map((x, i) => [x, count[i]])
  console.log(out)
}

Sample Input:

Output:

[ [ 'Val1', 2 ], [ 'Val2', 1 ] ]

References:

• map()
• flat()
• filter()