Google Apps Script: Comparing Arrays for Unique Values

Question

I'm working from the solution provided HERE to compare two arrays. The example provided returns values found in both arrays to Array1 (same) and values only found on one or the other two Array2 (diff).

ISSUE: When I apply it to my own script, valuesDATA returns nothing and valuesCheckSeeding returns ALL values from both arrays

DESIRED RESULT: I have two arrays that I'd either like to create a third out of, or only select values from the first array, valuesDATA which are NOT present in the second, valuesCheckSeeding. Using the solution above, I was trying to have all values not found in valuesCheckSeeding AND valuesDATA pushed to valuesDATA.

SAMPLE OF valuesDATA: "U09 F Harford FC Hill/Healey - A MD CMSA Girls Saturday U09 A/B North Premier - Top TID0118"

What am I doing wrong? I tinkered with changing matchfound==false and matchfound=true in the loop, but that still didn't give me the desired result.

MOST RELEVANT SNIPPET

var matchfound = false;

for (var i = 0; i < valuesDATA.length; i++) {
  matchfound=false;
    for (var j = 0; j < valuesCheckSeeding.length; j++) {
      if (valuesDATA[i] == valuesCheckSeeding[j]) {
        valuesCheckSeeding.splice(j, 1);
        matchfound=true;
        continue;
        }
        }
          if (matchfound==false) {
            valuesCheckSeeding.push(valuesDATA[i]);
            valuesDATA.splice(i, 1);
            i=i-1;
            }
          }

WORKIG SCRIPT EDITED FROM COMMENTS/ANSWERS BELOW

//UPDATE SEEDING SHEET
function updateSeedingSheet() {

var today = Utilities.formatDate(new Date(),Session.getScriptTimeZone(), "MM/dd/yyyy hh:mm a");   

//INPUT SHEET INFO
var inputCurrentRow = 4;
var inputCurrentColumn = 20;
var inputNumRows = 1000;
var inputNumColumns =1;

var ssInput = SpreadsheetApp.openById('1Wzg2BklQb6sOZzeC0OEvQ7s7gIQ07sXygEtC0CSGOh4');
var sheetDATA = ssInput.getSheetByName('DATAREF');
var rangeDATA = sheetDATA.getRange(inputCurrentRow, inputCurrentColumn, inputNumRows, inputNumColumns);
var valuesDATA = rangeDATA.getValues();


//SEEDING SHEET INFO
var seedingCurrentRow = 4;
var seedingCurrentColumn = 1;
var seedingNumRows = 1000;
var seedingNumColumns = 1;

var ssSeeding = SpreadsheetApp.openById('1DuCHeZ3zba-nHq-7vYTrylncPGqcA1J9jNyW9DaS3mU');
var sheetSeeding = ssSeeding.getSheetByName('Seeding');
var rangeCheckSeeding = sheetSeeding.getRange(4, 102, 1000, 1);
var columnToClear = sheetSeeding.getRange(seedingCurrentRow, seedingCurrentColumn, seedingNumRows, seedingNumColumns);
var valuesCheckSeeding = rangeCheckSeeding.getValues();


//METHOD TO FILTER
valuesCheckSeeding = valuesCheckSeeding.map(function(e){return e[0];}); //flatten this array
var filteredArr = valuesDATA.filter(function(e){
    return !(this.indexOf(e[0])+1);
},valuesCheckSeeding);
Logger.log(filteredArr);
Logger.log(filteredArr.length);

var rangeSeeding = sheetSeeding.getRange(seedingCurrentRow, seedingCurrentColumn, filteredArr.length, seedingNumColumns);

sheetSeeding.getRange('A1').setValue(today);
columnToClear.clearContent();
rangeSeeding.setValues(filteredArr);



/*
//ALTERNATIVE METHOD USING LOOPS
for (var i = 0; i < valuesDATA.length; i++) {
    for (var j = 0; j < valuesCheckSeeding.length; j++) {
      if (valuesDATA[i][0] == valuesCheckSeeding[j][0]) {
        valuesDATA.splice(i, 1);
        i--; //account for the splice
        break; //go to next i iteration of loop
          }
       }
     }
          Logger.log("VALUES DATA:" + valuesDATA);
          Logger.log("VALUES CHECK SEEDING: " + valuesCheckSeeding);         

//sheetSeeding.getRange('A1').setValue(today);
//rangeSeeding.clearContent();
//rangeSeeding.setValues(valuesDATA); //INCORRECT RANGE HEIGHT, WAS 71 BUT SHOULD BE 1000 - Is splice affecting this? 

*/

}//END FUNCTION

Answer 1

V8(ES2016 update):

• You can use newer and efficient set class

const array1 = [[1],[2],[3]],
array2 = [[1],[3],[4]],
set = new Set(array2.flat())
console.info(array1.filter(e => !set.has(e[0])))
//expected output [[2]]

---

• You're checking a 2D array. You'd need to use [i][0] and [j][0]
• You can try only splicing valuesDATA

Try

for (var i = 0; i < valuesDATA.length; i++) {
    for (var j = 0; j < valuesCheckSeeding.length; j++) {
      if (valuesDATA[i][0] == valuesCheckSeeding[j][0]) {
        valuesDATA.splice(i, 1);
        i--; //account for the splice
        break; //go to next i iteration of loop
        }
     }
}
Logger.log(valuesDATA);

---

Alternatively, try

valuesCheckSeeding = valuesCheckSeeding.map(function(e){return e[0];}); //flatten this array
var filteredArr = valuesDATA.filter(function(e){
    return !(this.indexOf(e[0])+1);
},valuesCheckSeeding);
Logger.log(filteredArr);