Find and clear a string of text with app script - google-apps-script

Question

So I'm working on creating something that will automatically create a spreadsheet of names and employees shifts. Below is the code that I'm using to copy and paste those names and shifts into the new sheet. I'm using a concatenate-like process to produce an outcome something like this: "6:00 AM - 1:00 PM." My problem now is that the function gets 52 rows on the first sheet and I don't always have 52 rows of data so it returns and pastes just the " - " of the function.
All I'm looking to do is have a function to find the " - " within an entire cell in a given range and clear it before I go to the sort function.
function onOpen() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var menuEntries = [ {name: "Update", functionName: "Update"}
];
ss.addMenu("Advanced", menuEntries);
}
function Update(){
var doc = SpreadsheetApp.openById('SOURCE ID GOES HERE');
var gs = doc.getSheets()[1];
var lastColumn = gs.getLastColumn();
var data = gs.getRange(2, 1, 52, lastColumn).getValues();
var destdoc = SpreadsheetApp.openById('DESTINATION ID GOES HERE');
var destsheet = destdoc.getSheets()[0];
//Day1
//Names
var fullNames1 = [];
for (var i = 0; i < data.length; i++) {
fullNames1.push([data[i][9]]);
}
var destRangeName = destsheet.getRange("A3").offset(0, 0, fullNames1.length);
destRangeName.setValues(fullNames1);
//shift
var shift1 = [];
for (var i = 0; i < data.length; i++) {
shift1.push([data[i][10] + ' - ' + data[i][11]]);
}
var destRangeName = destsheet.getRange("B3").offset(0, 0, shift1.length);
destRangeName.setValues(shift1);
//sort
var range1 = destsheet.getRange("A3:B54");
range1.sort([{column: 2, ascending: true}]);

Answer 1

You don't need to read a fixed range of 52 rows, because you can get only the populated rows via .getDataRange(). Instead of this:
var data = gs.getRange(2, 1, 52, lastColumn).getValues();
Use this.
var data = gs.getDataRange().getValues()
.slice(1); // Skip 1 header row
You've decoupled creation of the names and shift columns, try creating your new "shiftData" as a 2-D array with both names and the concatenated shift data. This is easier to maintain in future.
You are doing your sort on the range after writing to the spreadsheet, but you could do that entirely in javascript arrays before writing them out. For this to work, you need to provide a function that will give sort the comparison result for two elements, as a parameter.
The final Update() function is:
function Update(){
var doc = SpreadsheetApp.openById('SOURCE ID GOES HERE');
var gs = doc.getSheets()[1];
var data = gs.getDataRange().getValues()
.slice(1); // Skip 1 header row
var shiftData = [];
for (var i = 0; i < data.length; i++) {
shiftData.push([data[i][9], data[i][10] + ' - ' + data[i][11]]);
}
shiftData.sort(function(a,b) {
// sort by shift
return a[1] - b[1];
});
var destdoc = SpreadsheetApp.openById('DESTINATION ID GOES HERE');
var destsheet = destdoc.getSheets()[0];
var destRangeName = destsheet.getRange("A3")
.offset(0, 0, shiftData.length, shiftData[0].length);
destRangeName.setValues(shiftData);
}