Length of two dimensional array in Javascript/Google Apps Script

Question

I have a two dimensional array in a Google apps script

data = [[1, 2], [3, 4]];

Trying to get the length of data returns "Undefined". Why is that?

Logger.log(data.length) // Outputs "Undefined"

Update (full code):

data = sheet.getSheetValues(1, 1, 10, 2);
Logger.log("readSpreadSheet");
Logger.log(data);
Logger.log(data.length);

Log:

[14-02-10 15:05:05:592 CET] readSpreadSheet
[14-02-10 15:05:05:592 CET] [[tt0062622, 10.0], [tt0066921, 10.0], [tt0094721, 8.0], [tt0445934, 10.0], [tt0784972, 7.0], [tt1136608, 1.0], [tt0119116, 10.0],     [tt1195478, 7.0], [tt2234155, 1.0], [tt1675434, 9.0]]
[14-02-10 15:05:05:592 CET] undefined

Answer 1

You made a typo in your code... you wrote lenght instead of length

code :

data = sheet.getSheetValues(1, 1, 10, 2);
Logger.log("readSpreadSheet");
Logger.log(data);
Logger.log(data.length);

log:

data.length = 10