Xcode - Invalid character in source file (Replace " " with " ")

Question

I have a question about Xcode (Swift). Sometimes when I write an if statement. Something like this:

if(a == 2){
//do Sth
} else {
//do Sth
}

Xcode throws me an error: "Invalid character in source file" I know it is no big deal and fixed by clicking on "Fix-it" but I want to know what is the problem. That doesn't make sense to me...

My Xcode is on 7.2 and I am using Swift - I don't know if this is just a Swift problem.

Answer 1

I was having this problem. The way I solved it is by 1) copying whatever you have into Sublime Text or another code editor and having a look (you may need to enable viewing hidden characters). Mine had a code in there DC2 which is some sort of ASCII control character. For me it was caused by the fact that I had put the playground into manual execute and bound a keyboard shortcut to it that seemed to be entering that control character every time I executed it using the shortcut. I just changed the shortcut and removed the ASCII characters as I was able to see them in Sublime Text. (The link in the comments to the OP concerning left to right mode made no sense and didn't work for me.)

Answer 2

For me it's the ESC key - it's completely reproducible! If I go to search and hit ESC in the search window I also find the occurrences marked - and can replace those with nothing. But it's not shown even with "Show invisible"!

final solution: Bind ESC keybinding to "Cancel". It's that simple.