Variable value is not getting updated after adding an element to the array in apps script(Google Sheets)

Question

This is part of the code.

var newarray = [
  
  ["A","B"],
  
  ["C","D"]
  
  ];

var dimensions = newarray.length;

ss.getRange(15,8).setValue(dimensions);

newarray.push(["Bharat","Lata"])

ss.getRange(18,8).setValue(newarray.length);

ss.getRange(21,8).setValue(dimensions);

Numbers in 15th, 18th, 21st row

I was expecting that dimensions value will be equal to 3 after adding an element to the newarray.

Answer 1

This is happening because you're not updating the variable dimensions after pushing new row in newarray.

Try following modification:

var newarray = [["A","B"],["C","D"]];

var dimensions = newarray.length;

ss.getRange(15,8).setValue(dimensions);

newarray.push(["Bharat","Lata"])
 
dimensions = newarray.length;

ss.getRange(18,8).setValue(newarray.length); // you can use dimensions here too 

ss.getRange(21,8).setValue(dimensions);

Answer 2

You have to update also var dimensions = newarray.length; after updating newarray

function myFunction() {
  var sh = SpreadsheetApp.getActiveSheet()
  var newarray = [
    ["A", "B"],
    ["C", "D"]
  ];
  var dimensions = newarray.length;
  sh.getRange(15, 8).setValue(dimensions);
  newarray.push(["Bharat", "Lata"])
  dimensions = newarray.length;
  sh.getRange(18, 8).setValue(newarray.length);
  sh.getRange(21, 8).setValue(dimensions);
}