let someString = "  Swift Language  \\n"
let trimmedString = someString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceAndNewlineCharacterSet())
// "Swift Language"

Method stringByTrimmingCharactersInSet returns a new string made by removing from both ends of the String characters contained in a given character set.

We can also just remove only whitespace or newline.

Removing only whitespace:

let trimmedWhiteSpace = someString.stringByTrimmingCharactersInSet(NSCharacterSet.whitespaceCharacterSet())
// "Swift Language  \\n"

Removing only newline:

let trimmedNewLine = someString.stringByTrimmingCharactersInSet(NSCharacterSet.newlineCharacterSet())
// "  Swift Language  "

let someString = "  Swift Language  \\n"

let trimmedString = someString.trimmingCharacters(in: .whitespacesAndNewlines)
// "Swift Language"

let trimmedWhiteSpace = someString.trimmingCharacters(in: .whitespaces)
// "Swift Language  \\n"

let trimmedNewLine = someString.trimmingCharacters(in: .newlines)
// "  Swift Language  "

Note: all these methods belong to Foundation. Use import Foundation if Foundation isn’t already imported via other libraries like Cocoa or UIKit.