Import Data from Gmail into Google Spreadsheet - regex

Question

I have an email sent out on a daily basis that I need to pull data from to a Google Sheet. I have read on this and found a solution that worked for other's, but I've been unable to get it to work on mine. This is the code I've tried modifying:
function menu(e) {
var ui = SpreadsheetApp.getUi();
ui.createMenu('Macros')
.addItem('parse mail', 'email')
.addToUi();
}
function parseMail(body) {
var a=[];
var keystr="First Name : ,Last Name : ,Customer ID : ,Invoice : ";
var keys=keystr.split(",");
var i,p,r;
for (i in keys) {
p=keys[i]+"\n([a-zA-Z0-9\ \,\.]*)\n";
r=new RegExp(p,"m");
try {a[i]=body.match(p)[1];}
catch (err) {a[i]="no match";}
}
}
function email() {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var s = ss.getActiveSheet();
var threads = GmailApp.search('subject: "Fwd: ARB Subscription*"');
var a=[];
for (var i = 0; i < threads.length; i++) {
var messages = GmailApp.getMessagesForThread(threads[i]);
for (var j = 0; j < messages.length; j++) {
a[j]=parseMail(messages[j].getPlainBody());
}
}
var nextRow=s.getDataRange().getLastRow()+1;
var numRows=a.length;
var numCols=a.length[0];
s.getRange(nextRow,1,numRows,numCols).setValues(a);
}
I've tried modifying the code, but the error I am getting is Cannot convert Array to Object[][] Line 35. any advice would be greatly appreciated

Answer 1

Get the dimensions of the data range as below.
Also, when you are setting the values on the range the size of two-dimensional array a must match the size of the range.
var dataRange = s.getDataRange();
var nextRow = dataRange.getLastRow() + 1;
var numRows = dataRange.getNumRows();
var numCols = dataRange.getNumColumns();
s.getRange(nextRow,1,numRows,numCols).setValues(a);