I found this code on reddit that works quite well. Anyway, when I try to delete the information that I completed with the dropdown, or modify something, an undefined value shows up and I can not delete it. How could I do that?
Code:
function onEdit(e){
if(e.range.columnStart != 6 || e.oldValue == undefined) return;
e.range.setValue(e.oldValue+" | "+e.value);
}
Besides, when more than 1 option is added on my cell, an 'invalid' message shows up. How could I delete it? It's a default config from the Data Validation.


