Word Form of Big O Notation

Question

O of (the contents of the parentheses)

Is this the correct way to say an expression with big O notation in words, just as y=f(x) is read y equals f of x? The expression with the big O followed by parentheses is a function, right?

Answer 1

I've usually head big oh of x but as long as your audience know what you're talking about it doesn't really matter too much, unless you're working with a function O it's not likely that anyone will mistake you.
Unless you're working with little o as well. Little o doesn't seem to be used that often though so the chances for confusion should be pretty small.

Answer 2

If speaking of an algorithm, saying a specific algorithm is "O of n squared" is commonly used, especially in the vicinity of computer scientists.