TypeError: Cannot read property 'length' of undefined (line 13, file “Code”)

Question

This is my first time working with javascript and I'm just messing around in google sheets.

Currently, I have a 2D array which contains all of the names of the sheets in the first position and some ranges within those sheets in the second position, I'm trying to step through the array and change all of the spaces within the ranges to 0. I've got it to a point where the script changes the first ranges of the sheets to 0 barring the last 2 sheets for some reason

function CompButton(){
  var event = 0
  var sheets = [
    ['Rebel_Outpost',"D6:D14","D18:D23","I6:I13","I17","I21:I23","N6:N22","N26:N34","S6:S21","S26:S31"],
    ['Advanced_Rebel',"D6:D9","D13","D17","D21:D25","I6:I20","I24","I28","N6:N20"],
    ['Market',"D7:D16","D20:D23","J7:J12","J16:J18","J22:J24","P7:P17","P21:P29"],
    ['Civilian_Shops',"D6:D18","D22:D36","I6:I12","I16","I20:I26","I30:I32","N6:N15","S6:S23","S30:S36"],
    ['Ground_Vehicles',"D7:D13","D17:D26","D30:D34","G7:G13","G17:G26","G30:G34"],
    ['Air_Vehicles',"D7:D22","G7:G22"],
    ['Water_Vehicles',"D7:D11","G7:G11"] 
  ];
  while (event < 7){
    for (var i = 1; i < sheets[event][i].length; i++){
      var sheet = SpreadsheetApp.getActive().getSheetByName(sheets[event][0]); 
      sheet.getRange(sheets[event][1]).setValue(0);
      event++;
    }
  }
}

https://gyazo.com/3f59c6fda652681667010058092c8ae7

if u want access to the sheet to test ill post it below

https://docs.google.com/spreadsheets/d/1bv6Fn6oKw4KaEM-xke0dOd87nVw2xk3W42Nnc1sKdJQ/edit?usp=sharing

https://script.google.com/d/12LMcV_meIdGgKANTeQjPcfMr2wC2ZdlZp_jxPRTAyCLTR8kJUHDuBbmu/edit?mid=ACjPJvE8t2PeFTxeOvw1nJ3Wif_B9lFXlFGCTluqR7XBLSsC9zWuQYo-ou_c1cJYw1MUP2njhNE-aZMqJ0NaJBspj91BQfD_p-o5n3JK6WgK2LZ_Sbjba5cTSN-qDOB9M5tYJy0KtE5DABw&uiv=2

Answer 1

I think I got it now:

 var sheets = [ ['Rebel_Outpost',"D6:D14","D18:D23","I6:I13","I17","I21:I23","N6:N22","N26:N34","S6:S21","S26:S31"], ['Advanced_Rebel',"D6:D9","D13","D17","D21:D25","I6:I20","I24","I28","N6:N20"], ['Market',"D7:D16","D20:D23","J7:J12","J16:J18","J22:J24","P7:P17","P21:P29"], ['Civilian_Shops',"D6:D18","D22:D36","I6:I12","I16","I20:I26","I30:I32","N6:N15","S6:S23","S30:S36"], ['Ground_Vehicles',"D7:D13","D17:D26","D30:D34","G7:G13","G17:G26","G30:G34"], ['Air_Vehicles',"D7:D22","G7:G22"], ['Water_Vehicles',"D7:D11","G7:G11"] ]; function zeroRanges(sheetsArray) { for(var sheetItem of sheetsArray) { var sheetName=sheetItem[0]; console.log("Working on sheet \""+sheetName+"\""); for(var rangeItemIndex=1; rangeItemIndex<sheetItem.length; rangeItemIndex++) { var range=sheetItem[rangeItemIndex]; console.log("--Zeroing range\""+range+"\""); // uncomment next 2 lines // var sheet = SpreadsheetApp.getActive().getSheetByName(sheetName); // sheet.getRange(range).setValue(0); } } } zeroRanges(sheets);

I wrote a function, zeroRanges that you pass the sheets to by using zeroRanges(sheets) . This way you can re-use it.
When you copy the code, uncomment the 2 lines that use the SpreadsheetApp - I've commented them out here so we can see in the console log that the function is working (hoping the commented code is correct).
You can comment-out/remove the console.log lines.

Answer 2

I'm not sure what exactly you're trying to do here but perhaps you'll find the below syntax more readable.

sheets.map(sheet => {
    sheet.map((el, index) => {
        if(index !== 0) {
            // Perform operation on el
        }
    })
})

For reference see map and forEach .

This post might not answer the original question but it certainly would help as an alternative.