Google Script array value undefined - arrays

Question

i wrote a code that should take a value from a cell and than convert it to the string and than into the array. its working fine. I can see the value of arr in Logs as an array with the input of the cell. For example, in the cell are " dog, cat " and tha arr value in Logs is [dog, cat].
But after i create this array, i would like to make a loop on it. And than i become in Logs, that arr is undefined. Can somebody help me please? im working on it for 2 days :(
Here is my code:
function animal (s,z){
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName('Sheet1');
var range = sheet.getRange("SM");
var columnNumber = getColumnNumberOfSM(s);
var rowNumber = getRowNumberOfSM(z);
var colAction = columnNumber + 1;
var action = sheet.getRange(rowNumber, colAction, 1, 1).getValues();
var bar = action.toString();
var arr = [{}];
arr = bar.split(", ");
//return arr; // returns an array [dog, cat]
var foo = arr; // underfined
for (var i = 0; i <= foo.length; ++i) {
if (foo[i] == "dog") {
Logger.log(upload());
}
}
}
now i edit my code and its working fine,but only with "dog" but not with "cat"
function animal(){
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sheet = ss.getSheetByName('Sheet1');
var action = sheet.getRange("C3").getValue();
var bar = action.toString();
var arr = bar.split(", ");
for (var i = 0; i <= arr.length; ++i) {
if (arr[i] == "dog") { // works
Logger.log(upload());
}
if (arr[i] == "cat") { // doesn't work
Logger.log(upload());
}
}
}

Answer 1

You don't need to initiate arr as blank you can directly initialize it as a result to split method , also one point I didn't get is why do you need to assign arr to foo? You can directly iterate through arr.length and perform the required operation.
Here's my working snippet.
var parts = path.split(",");
for (var i = 0; i < parts.length; i++) {
if (parts[i] == 'dog'){
Logger.log(parts[i]);
}
}