Conditional combine of array objects Google apps script - google-apps-script

Question

I have a two dimensional array which elements needs to be combined if two of the elements of the sub arrays are equal.
Example:
I have this data:
Name
Date start
Date end
First
startDate1
endDate1
Second
startDate2
endDate2
Third
startDate1
endDate2
Fourth
startDate1
endDate1
Fifth
startDate1
endDate1
Sixth
startDate3
endDate2
I need this data:
Name
Date start
Date end
First, Fourth, Fifth
startDate1
endDate1
Second
startDate2
endDate2
Third
startDate1
endDate1
Sixth
startDate3
endDate2
The data is represented this way for example:
var event1 = [name, startDate1, endDate1];
var event2 = [name, startDate2, endDate2];
var event3 = [name, startDate1, endDate2];
var event4 = [name, startDate1, endDate1];
var event5 = [name, startDate1, endDate1];
var event6 = [name, startDate3, endDate2];
var allEvents = [event1, event2, event3, event4, event5, event6 ]
And I need to combine the elements with concatenated names if both start and end dates are equal.
Any help is much appreciated.

Answer 1

I'll leave it up to you where to put the results but try this:
function test() {
try {
var ss = SpreadsheetApp.getActiveSpreadsheet();
var sh = ss.getSheetByName("Test");
var unique = [];
var data = sh.getRange(1,1,sh.getLastRow(),sh.getLastColumn()).getValues();
unique.push(data[1]);
var append = true;
for( var i=2; i<data.length; i++ ) {
append = true;
for( var j=0; j<unique.length; j++ ) {
if( ( data[i][1] === unique[j][1] ) && ( data[i][2] === unique[j][2] ) ) {
unique[j][0] = unique[j][0]+", "+data[i][0];
append = false;
break;
}
}
if( append ) unique.push(data[i]);
}
console.log(unique);
}
catch(err) {
console.log(err);
}
}
consol.log:
8:15:15 AM Info [ [ 'First, Fourth, Fifth', 'startDate1', 'endDate1' ],
[ 'Second', 'startDate2', 'endDate2' ],
[ 'Third', 'startDate1', 'endDate2' ],
[ 'Sixth', 'startDate3', 'endDate2' ] ]