Remove leading and trailing whitespace in Swift

Sure, in Swift, you can remove leading and trailing whitespaces from a string using the trimmingCharacters(in:) method. The in parameter takes in a CharacterSet, which you can use to specify which characters you want to trim from the string.

Here's an example:

let str = "   Hello, World!    "
let trimmedStr = str.trimmingCharacters(in: .whitespaces)
print(trimmedStr) // Output: "Hello, World!"

In this example, we first define a string str which has leading and trailing whitespaces. We then call the trimmingCharacters(in:) method and pass in the whitespaces CharacterSet to trim the whitespaces. The resulting string is stored in trimmedStr and printed using the print() method, which outputs Hello, World! without the leading and trailing whitespaces.