To remove leading and trailing whitespaces:
let trimmedString = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
Swift 3 / Swift 4:
let trimmedString = string.trimmingCharacters(in: .whitespaces)
To remove leading and trailing whitespaces:
let trimmedString = string.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
Swift 3 / Swift 4:
let trimmedString = string.trimmingCharacters(in: .whitespaces)