Find and Replace on row1 google sheets function - google-apps-script

Question

Very new to this, I am trying to Find and Replace on row1 only
I want to find aa and replace it with ZZZ
I am trying two different ways but neither work
Thanks
first way:
function replace3() {
var sheet = SpreadsheetApp.getActiveSheet();
var lc = sheet.getMaxColumns();
var range = sheet.getRange("a1:z1");
var values = range.getValues();
for (var col in values[1]) {
if (values[0][col] ='aa') {
values[0][col] = 'ZZZ';
}
}
range.setValues(values);
}
Second Way:
function replace2() {
var sheet = SpreadsheetApp.getActiveSheet();
var lc = sheet.getMaxColumns();
var range = sheetname.getRange(1, 1, 1, lc);
var values = range.getValues();
for (var i = 0; i <= lc; i++) {
if (values[0][i] ='aa') {
values[0][i] = 'ZZZ';
}
}
range.setValues(values);
}

Answer 1

How about the following modofications?
For replace3()
The index of array starts 0.
When values are compared at if, please use ==.
Modified script :
function replace3() {
var sheet = SpreadsheetApp.getActiveSheet();
var lc = sheet.getMaxColumns();
var range = sheet.getRange("a1:z1");
var values = range.getValues();
for (var col in values[0]) { // Modified
if (values[0][col] =='aa') { // Modified
values[0][col] = 'ZZZ';
}
}
range.setValues(values);
}
For replace2()
sheetname is not declared.
When values are compared at if, please use ==.
Modified script :
function replace2() {
var sheet = SpreadsheetApp.getActiveSheet();
var lc = sheet.getMaxColumns();
var range = sheet.getRange(1, 1, 1, lc); // Modified
var values = range.getValues();
for (var i = 0; i <= lc; i++) {
if (values[0][i] == 'aa') { // Modified
values[0][i] = 'ZZZ';
}
}
range.setValues(values);
}
Other method :
Also you can achieve it using map().
Sample script :
function sample() {
var sheet = SpreadsheetApp.getActiveSheet();
var range = sheet.getRange("a1:z1");
var values = range.getValues();
var data = values[0].map(function(e){return e == 'aa' ? 'ZZZ' : e});
range.setValues([data]);
}
If I misunderstand your question, please tell me. I would like to modify.