Another thing, other than Int being spelled as INt and println having a capital P, you also have to have equal spaces on either side of your operator "!=". Either (a != 0) but you don't even need the parenthesis in this instance.
var a:Int = 5
if a != 0 {
println("Hello world")
}
Hope that helps you. In a lot of cases you can have equal spaces or equal no spaces on either side of your operand, I think maybe on in assignments. a=5 or a = 5, but I
a= 5 or a =5 is wrong and will give an error. This is due to Swift's ability to do operator overloading. You could create an operator called a= that does something you define. The compiler looks at those spaces or lack or spaces due to this reason.
I am by no means a Swift expert, I've only been using it since June of last year ;-)
No really I just do this stuff as a hobby and this answer may already be answered by someone else, but I knew the answer to this one so I wanted to jump in and contribute where I could.