Remove special characters from a string in Swift

In this tutorial, I will show you how to remove special characters from a string in Swift.

I will go with the basic and easy method first. (It will be useful or not depending on the project that you are working on).

Remove special characters from a string using array of special characters

Steps involved:

• Will create an array containing all the special characters. (You can easily extend or reduce the characters from it as per your requirement)
• Then we will give our string to check.
• We will fetch char by char in a for loop. If a character is not from the special character array then we will append that character to our new string finalString.

I have created this piece of code:

import Foundation
var specialChar = ["+", "-", "&", "|", "!", "(", ")", "{", "}", "[", "]", "^",
            "~", "*", "?", ":","\\", "@","`","#","$","%","_","/",",",".",":","\""]
var string = "HeyTher\"e`@ihh"
var finalString = ""
for char in string {
    if !specialChar.contains(String(char)) {
        finalString.append(char)
    }
}
string = finalString
print(string)

Note that: I personally don’t like this method as this will not give you accurate results in all cases.

It’s better to use the opposite to it.

I could create an array that contains a to z, A to Z and 0-9. If any character is found other than this, we can easily remove that. This method will be the most effective.

We can use Regular Expression to achieve the above-mentioned best method:

import Foundation

func codespeedy(from string: String) -> String {
    let myPattern = try! NSRegularExpression(pattern: "[^a-zA-Z0-9 ]", options: .caseInsensitive)
    let range = NSRange(location: 0, length: string.count)
    let finalString = myPattern.stringByReplacingMatches(in: string, options: [], range: range, withTemplate: "")
    return finalString
}

let myString = "Wel$%come to Co~^`deSp))eedy%"
let result = codespeedy(from: myString)
print(result)

Output:

Welcome to CodeSpeedy

[^a-zA-Z0-9 ] This is the part where I have declared what to keep in my string and what not.
I have inserted a space at the end of that pattern otherwise, it will also remove the spaces and the output would be like this:

WelcometoCodeSpeedy

Using punctuationCharacters

import Foundation
var string = "hello, @ Nice to #meet you"
extension String {
  var removedSpecialCharacters: String {
    return self.components(separatedBy: CharacterSet.punctuationCharacters).joined(separator: "")
  }
}



print(string)
print(string.removedSpecialCharacters)

Output:

hello, @ Nice to #meet you
hello Nice to meet you

This will also not work for some special characters like:  ~ and `.