[JS CS3] Merging table columns

Question

Hi all,
What's the fastest way to merge columns in a table?
I'm using the following loop to merge the 4th and 5th columns in my table:
for( var f = myTable.rows.length-1; f >= 0; f-- ){
myTable.columns[3].cells[f].merge (myTable.columns[4].cells[f])
It works, but I'm working on a large table (120 pages worth) and have many instance where I need to merge columns. Using the loop above, the script takes hours to run. Is there a faster way to merge columns while keeping the rows intact?
Thanks,
Michael

Answer 1

I've just done some time testing with CS4 and found the following:
table = app.documents[0].stories[0].tables[0];
start = new Date();
for (var n = 0; 100 > n; n++) {
  cells = table.cells;
  for (var j = 0; cells.length > j; j++) {
    cells[j].contents = "James";
end = new Date();
alert(end - start);
takes just about the same time to run as:
table = app.documents[0].stories[0].tables[0];
start = new Date();
rowCount = table.rows.length;
columnCount = table.columns.length;
for (var n = 0; 100 > n; n++) {
  for (var c = 0; columnCount > c; c++) {
    for (var r = 0; rowCount > r; r++) {
      table.cells.item(c + ":" + r).contents = "Harry";
end = new Date();
alert(end - start);
While this version takes about half as long again:
table = app.documents[0].stories[0].tables[0];
start = new Date();
rowCount = table.rows.length;
columnCount = table.columns.length;
for (var n = 0; 100 > n; n++) {
  for (var c = 0; columnCount > c; c++) {
    for (var r = 0; rowCount > r; r++) {
      table.rows[r].cells[c].contents = "Harry";
end = new Date();
alert(end - start);
None of which is particularly surprising. But when I compared the following two scripts, I was astonished by the result:
table = app.documents[0].stories[0].tables[0];
start = new Date();
rowCount = table.rows.length;
columnCount = table.columns.length;
for (var n = 0; 100 > n; n++) {
  table.cells.everyItem().contents = "Harry";
end = new Date();
alert(end - start);
table = app.documents[0].stories[0].tables[0];
start = new Date();
rowCount = table.rows.length;
columnCount = table.columns.length;
for (var n = 0; 100 > n; n++) {
  table.cells.itemByRange(0, -1).contents = "George";
end = new Date();
alert(end - start);
The latter, using itemByRange was about a third faster than using everyItem(). 1800 milliseconds to 2700 on a 4 x 10 table.
Dave