Single vs Double Quotations


#1

When do you use "double quotations" and when do you use 'single quotations'?
Are they interchangeable?


#2

It is conventional to always use double quotes until otherwise specified. They are usually interchangeable without error, but always use double quotes if not specified.


#3

In javascript, for example, you use single quotation inside of a double quotation for convenience.
For example:

windows.alert("He said: 'hello'")

or you could just write

windows.alert("He said: \"hello\"")

On top of everything. Single and double quotations are interchangeable. But it would be better to use double quotation.