If you use simply :
var values = SpreadsheetApp.getActiveSheet().getDataRange().getValues()
You will get a 2 Dimension array of all the data in the sheet indexed by rows and columns.
So to get the value in column A, row1 you use values[0][0]
, values[1][0]
for columnA, row 2, values[0][2]
for column C row1, etc…
If you need to iterate in a for loop (in a single column) :
for (n = 0; n < values.length; ++n) {
var cell = values[n][x] ; // x is the index of the column starting from 0
}
If you need to iterate in a for loop (in a single row) :
for (n = 0; n < values[0].length; ++n) {
var cell = values[x][n] ; // x is the index of the row starting from 0
}