String extensions for String class in Swift

String+Extensions.swift

//
//  String+Extensions.swift
//
//  Created by Rigoberto Sáenz Imbacuán (https://www.linkedin.com/in/rsaenzi/)
//  Copyright © 2019. All rights reserved.
//

import Foundation

extension String {
    
    func removeCharacters(from forbiddenChars: CharacterSet) -> String {
        let passed = self.unicodeScalars.filter { !forbiddenChars.contains($0) }
        return String(String.UnicodeScalarView(passed))
    }
    
    func removeCharacters(from: String) -> String {
        return removeCharacters(from: CharacterSet(charactersIn: from))
    }
    
    func removeNonNumericCharacters() -> String {
        return self.removeCharacters(from: CharacterSet.decimalDigits.inverted)
    }
    
    static func getRandomString(length: Int) -> String {
        let letters = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"
        return String((0..<length).map{ _ in letters.randomElement()! })
    }
}