Standard for loop

Question

In the lesson is reported that standard for loop has three parameters.
I think, that like in other languages, they are not mandatory, but the semicolons are mandatory, to understand which parameter is omitted.

Is it right?

Answer 1

I mean:
for (expr1;expr2;) // missing increment parameter
for (expr1;;expr2) // missing test parameter
for (;expr1;expr2) // missing init parameter