Replace certain cell values in a column

Question

Disclaimer: I am Newb. I understand scripting a little, but writing it is a pain for me, mostly with loops and arrays, hence the following.

I am attempting to pull all of the data from a specific column (in this case H [8]), check each cell's value in that column and if it is a y, change it to Yes; if it's n, change it to No; if it's empty, leave it alone and move onto the next cell.

Here's what I have so far. As usual, I believe I'm pretty close, but I can't set the value of the active cell and I can't see where I'm messing it up. At one point I actually changed ever value to Yes in the column (so thankful for undo in these cases).

Example of Sheet:

..... COL-H  
r1... [service] <-- header  
r2... y  
r3... y  
r4... n  
r5... _  <-- empty  
r6... y  

Intent: Change all y's to Yes and all n's to No (skip blank cells).

What I've tried so far:

Function attempt 1

function Thing1() {
  var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("mySheet");
  var lrow = ss.getLastRow();
  var rng = ss.getRange(2, 8, lrow - 1, 1);
  var data = rng.getValues();

  for (var i=0; i < data.length; i++) {
    if (data[i][0] == "y") {
      data[i][0] == "Yes";
    }
  }
}

Function attempt 2

function Thing2() {
  var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName("mySheet");
  var lrow = ss.getLastRow();
  var rng = ss.getRange(2, 8, lrow - 1, 1);
  var data = rng.getValues();

  for (var i=0; i < data.length; i++) {
    if (data[i][0] == "n") {
      data.setValue("No");
    } else if (data[i][0] == "y") {
      data.setValue("Yes");
    }
  }
}

Usage:

Once I'm done here, I want to modify the function so that I can target any column and change one value to another (I already have a method for that, but I need to be able to set the value). It would be like so: =replace(sheet, col, orig_value, new_value). I will post it as well below.

Thanks in advance for the help.

---

Completed Code for searching and replacing within a column

function replace(sheet, col, origV1, newV1, origV2, newV2) {
  // What is the name of the sheet and numeric value of the column you want to search?
  var sheet = Browser.inputBox('Enter the target sheet name:');
  var col = Browser.inputBox('Enter the numeric value of the column you\'re searching thru');

  // Add old and new targets to change (Instance 1):
  var origV1 = Browser.inputBox('[Instance 1:] What old value do you want to replace?');
  var newV1 = Browser.inputBox('[Instance 1:] What new value is replacing the old?');

  // Optional - Add old and new targets to change (Instance 2):
  var origV2 = Browser.inputBox('[Instance 2:] What old value do you want to replace?');
  var newV2 = Browser.inputBox('[Instance 2:] What new value is replacing the old?');

  // Code to search and replace data within the column
  var ss = SpreadsheetApp.getActiveSpreadsheet().getSheetByName(sheet);
  var lrow = ss.getLastRow();
  var rng = ss.getRange(2, col, lrow - 1, 1);
  var data = rng.getValues();

  for (var i=0; i < data.length; i++) {
    if (data[i][0] == origV1) {
      data[i][0] = newV1;
    } else if (data[i][0] == origV2) {
      data[i][0] = newV2;
    }
  }
  rng.setValues(data);
}

Hope this helps someone out there. Thanks Again @ScampMichael!

Solution

The array named data was created from the values in the range and is independent of the spreadsheet after it is created so changing an element in the array does not affect the spreadsheet. You must modify the array and then put the whole array back where it came from.

  for (var i=0; i < data.length; i++) {
    if (data[i][0] == "n") {
      data[i][0] = "No";
    } else if (data[i][0] == "y") {
      data[i][0] = "Yes";
    }
  }
rng.setValues(data); // replace old data with new
}