How to replace a text in a complete Google Spreadsheet - replace

Question

I try to make a script which replace a value (e.g. 1 to x). This is my script:
function myOwnReplaceTest(){
var ss = SpreadsheetApp.getActiveSheet();
var sheet = ss.getName();
for (var r = 1; r <= ss.getLastRow(); ++r) {
for (var c = 1; c <= ss.getLastColumn(); ++c) {
var sr = ss.getRange(r, c).getValue();
var re = sr.toString().replace(1,'x');
ss.getRange(r, c).setValue(re);
}
}
}
It works fine, but very very slow in a bigger list (eg. 1000 lines and 10 columns).
When i test the same function about "STRG+H" it works in 5 Seconds.
Does anyone have a tip for me how I can make my script faster?
Thanks in advance.

Answer 1

Based on the article on which I commented, the following should be faster because it writes only once. I had to rewrite the loops to get my indices to match up nicely.
function myOwnReplaceTest(){
var ss = SpreadsheetApp.getActiveSheet();
var sheet = ss.getName();
var newVals = new Array(ss.getLastRow());
for (var r = 0; r < ss.getLastRow(); r++) {
newVals[r]=new Array(ss.getLastColumn()-1);
for (var c = 0; c < ss.getLastColumn(); c++) {
var sr = ss.getRange(r+1, c+1).getValue();
var re = sr.toString().replace(1,'x');
newVals[r][c]=re;
//ss.getRange(r, c).setValue(re);
}
}
//Browser.msgBox(newVals);
ss.getRange(1,1,newVals.length,newVals[0].length).setValues(newVals);
}
Presumably it can be further souped up by reading the data into an array, too.
Edit: Here is what that looks like.
function myOwnReplaceTest(){
var ss = SpreadsheetApp.getActiveSheet();
var sheet = ss.getName();
var newVals = new Array(ss.getLastRow());
var allSr = ss.getRange(1,1,ss.getLastRow(),ss.getLastColumn());
//Browser.msgBox(allSr.getValues());
for (var r = 0; r < ss.getLastRow(); r++) {
newVals[r]=new Array(ss.getLastColumn()-1);
for (var c = 0; c < ss.getLastColumn(); c++) {
//var sr = ss.getRange(r+1, c+1).getValue();
var sr = allSr.getCell(r+1, c+1).getValue();
var re = sr.toString().replace(1,'x');
newVals[r][c]=re;
//ss.getRange(r, c).setValue(re);
}
}
//Browser.msgBox(newVals);
ss.getRange(1,1,newVals.length,newVals[0].length).setValues(newVals);
}
I would hope that will speed it up a little further. The other tweak might be to not call getLastColumn() so many times, but I imagine that is not a big factor. The key here is that all the operations in the inner for loop are now in memory.