用JavaScript创建二维矩阵

Question

I'm using Google Visualization API to create a table. In order to setup the head of the column, this is valid matrix:

var rows = [['Id', 'Site', 'Site Code', 'TC 10', 'TC9x Test', 'Tc9x Build', 'Oracle Autotest', 
                        'Database', 'Baseline', 'push_windows', 'push_unix', 'license', 'tcx', 
                        'eng', 'perforce_proxy', 'volume_server', 
                        'Windows Ref Unit Location', 'Unix Ref Unit Location',
                        'Windows RTE Location', 'Unix RTE Location', 'Windows Toolbox Location', 
                        'Unix Toolbox Location', 'UGII License File', 'UGS License Server', 'Unix Dev Units', 
                        'Unix Devop Path', 'Perforce Proxy Path', 'Primary Contact', 'Secondary Contact', 'Num Users']];

I understand rows is a 1xn matrix (which is valid).

Now, I have to change my code, and load the columns from the database. Now, suppose all my columns are stores in columns , an array. How could I create similar matrix as show in rows above? I wrote the following code:

var rows = [[]];
for(var i = 0; i < columns.length; i++){
    rows[0][i] = columns[i];
}

However, I'm getting the following error:

Not a valid 2D array.

Answer 1

Works fine:

var rows = [[]];
var columns = ["a","b","c"];
for(var i = 0; i < columns.length; i++){
  rows[0][i] = columns[i];
}

So what does that error mean? or maybe you need to check your columns Array