Diffrernce between in single and double quotes in servicenow?

[Reddy2]

I just wanted  to update static value  in  work notes;

like test message

for that i need to use 

currnet.work_notes = 'Test message'; or 

current.work_notes ="Test message";

which is the correct one.

[Prateek kumar]

Both are correct, it is just the user preference.

 https://www.w3schools.com/js/js_strings.asp

[Reddy2]

but the worknotes not updating in both the cases

[Prateek kumar]

It will update in both the cases. can you tell me what exactly you are looking.