Xcode gives 3 syntax errors dealing with Stray '\342' in program

I am working on a simple project in Objective-C in Xcode and I'm getting some stray/ errors about the following line of code:

if(celsius < −273.15) {
        NSLog(@"It is impossible to convert temperatures less than −273.15 degrees Celsius, because this is absolute zero, the coldest possible temperature.");
    }

It's actually only about the first line, but I wanted to give some context.

Any suggestions?

I've looked it up here on SO, but everyone else's error hasn't had such simple code like mine, although it appears they have a common problem o开发者_高级运维f having the wrong encoding for certain punctuation, perhaps?

It's got to be just some syntax this on my if statement..

UPDATE:

It looks as though it also displays 2 other stray errors:

Stray '\210' Stray '\222'

− != -

Your minus, isn't a minus.

Make sure that your " characters are straight up and down (and not of the left/right slanted variety).