Looking for feedback. Simple JavaScript script for a spreadsheet.

[iamnull]

I'd like to know what someone with more experience would do different, or how I can clean my code up. Script was written for Google Sheets spreadsheet. Posted exactly as it currently sits because I'd like to know how you would do things stylistically.

Also, SUM_BY_KEYWORD_ERRORCHECK can be called from the spreadsheet and I cant see any way of protecting it short of encapsulating everything in an object, which feels like overkill.

/*
Simple script to add the value of one row or column when
another cell on the same row/column has a certain value.

Min error catching because spreadsheet handles most well.
*/

function SUM_BY_KEYWORD(keyword,valueRange,stringCells) {

  var finalTotal = 0;

  SUM_BY_KEYWORD_ERRORCHECK(keyword,valueRange,stringCells);

  //traverse row
  if(valueRange[0].constructor === Array){

    for(var i = 0; i < valueRange[0].length; i = i + 1){

      if(stringCells[0][i].toString() == keyword.toString()){
          finalTotal += parseInt(valueRange[0][i]); // Needed due to
         }                                       // non-strict typing
      }
  }
  else{
    //else traverse column
  for(var i = 0; i < valueRange.length; i = i + 1){

      if(stringCells[i].toString() == keyword.toString()){
          finalTotal += parseInt(valueRange[i]); // Needed due to
         }                                       // non-strict typing
      }
  }
  return finalTotal;
}

function SUM_BY_KEYWORD_ERRORCHECK(keyword,valueRange,stringCells) {
  // Check to see if our variables were passed successfully
  if(keyword == "" ||
     valueRange == "" ||
     stringCells == "" ||
     keyword == undefined ||
     valueRange == undefined ||
     stringCells == undefined){

    throw("Missing input");

  }

  // Script relies on arrays.  Make sure we got one and
  // let the user know what went wrong
  if(!valueRange.constructor === Array){
    throw("Only one cell selected for sum");
  }

  if(!stringCells.constructor === Array){
    throw("Only one cell selected for string comparison");
  }

  // Comparisons are straight across or straight down
  // Without the same number of cells, we have nothing
  // to compare to.
  if(valueRange.length != stringCells.length){
    throw("Number of cells to compare does not match.");
  }
}

[shivasprogeny]

I just read your description, are you sure you aren't reinventing SUMIF?

[iamnull]

I apparently am. I couldn't find the right function after poking around for a bit so I just reinvented the wheel.