Formatting Phone number in Swift
Manipulations with characters in String are not very straightforward. You need following:
Swift 2.1
let s = "05554446677"
let s2 = String(format: "%@ (%@) %@ %@ %@", s.substringToIndex(s.startIndex.advancedBy(1)),
s.substringWithRange(s.startIndex.advancedBy(1) ... s.startIndex.advancedBy(3)),
s.substringWithRange(s.startIndex.advancedBy(4) ... s.startIndex.advancedBy(6)),
s.substringWithRange(s.startIndex.advancedBy(7) ... s.startIndex.advancedBy(8)),
s.substringWithRange(s.startIndex.advancedBy(9) ... s.startIndex.advancedBy(10))
)
Swift 2.0
let s = "05554446677"
let s2 = String(format: "%@ (%@) %@ %@ %@", s.substringToIndex(advance(s.startIndex, 1)),
s.substringWithRange(advance(s.startIndex, 1) ... advance(s.startIndex, 3)),
s.substringWithRange(advance(s.startIndex, 4) ... advance(s.startIndex, 6)),
s.substringWithRange(advance(s.startIndex, 7) ... advance(s.startIndex, 8)),
s.substringWithRange(advance(s.startIndex, 9) ... advance(s.startIndex, 10))
)
Code will print
0 (555) 444 66 77
Swift 3 & 4
This solution removes any non-numeric characters before applying formatting. It returns nil if the source phone number cannot be formatted according to assumptions.
Swift 4
The Swift 4 solution accounts for the deprecation of CharacterView and Sting becoming a collection of characters as the CharacterView is.
import Foundation
func format(phoneNumber sourcePhoneNumber: String) -> String? {
// Remove any character that is not a number
let numbersOnly = sourcePhoneNumber.components(separatedBy: CharacterSet.decimalDigits.inverted).joined()
let length = numbersOnly.count
let hasLeadingOne = numbersOnly.hasPrefix("1")
// Check for supported phone number length
guard length == 7 || (length == 10 && !hasLeadingOne) || (length == 11 && hasLeadingOne) else {
return nil
}
let hasAreaCode = (length >= 10)
var sourceIndex = 0
// Leading 1
var leadingOne = ""
if hasLeadingOne {
leadingOne = "1 "
sourceIndex += 1
}
// Area code
var areaCode = ""
if hasAreaCode {
let areaCodeLength = 3
guard let areaCodeSubstring = numbersOnly.substring(start: sourceIndex, offsetBy: areaCodeLength) else {
return nil
}
areaCode = String(format: "(%@) ", areaCodeSubstring)
sourceIndex += areaCodeLength
}
// Prefix, 3 characters
let prefixLength = 3
guard let prefix = numbersOnly.substring(start: sourceIndex, offsetBy: prefixLength) else {
return nil
}
sourceIndex += prefixLength
// Suffix, 4 characters
let suffixLength = 4
guard let suffix = numbersOnly.substring(start: sourceIndex, offsetBy: suffixLength) else {
return nil
}
return leadingOne + areaCode + prefix + "-" + suffix
}
extension String {
/// This method makes it easier extract a substring by character index where a character is viewed as a human-readable character (grapheme cluster).
internal func substring(start: Int, offsetBy: Int) -> String? {
guard let substringStartIndex = self.index(startIndex, offsetBy: start, limitedBy: endIndex) else {
return nil
}
guard let substringEndIndex = self.index(startIndex, offsetBy: start + offsetBy, limitedBy: endIndex) else {
return nil
}
return String(self[substringStartIndex ..< substringEndIndex])
}
}
Swift 3
import Foundation
func format(phoneNumber sourcePhoneNumber: String) -> String? {
// Remove any character that is not a number
let numbersOnly = sourcePhoneNumber.components(separatedBy: CharacterSet.decimalDigits.inverted).joined()
let length = numbersOnly.characters.count
let hasLeadingOne = numbersOnly.hasPrefix("1")
// Check for supported phone number length
guard length == 7 || (length == 10 && !hasLeadingOne) || (length == 11 && hasLeadingOne) else {
return nil
}
let hasAreaCode = (length >= 10)
var sourceIndex = 0
// Leading 1
var leadingOne = ""
if hasLeadingOne {
leadingOne = "1 "
sourceIndex += 1
}
// Area code
var areaCode = ""
if hasAreaCode {
let areaCodeLength = 3
guard let areaCodeSubstring = numbersOnly.characters.substring(start: sourceIndex, offsetBy: areaCodeLength) else {
return nil
}
areaCode = String(format: "(%@) ", areaCodeSubstring)
sourceIndex += areaCodeLength
}
// Prefix, 3 characters
let prefixLength = 3
guard let prefix = numbersOnly.characters.substring(start: sourceIndex, offsetBy: prefixLength) else {
return nil
}
sourceIndex += prefixLength
// Suffix, 4 characters
let suffixLength = 4
guard let suffix = numbersOnly.characters.substring(start: sourceIndex, offsetBy: suffixLength) else {
return nil
}
return leadingOne + areaCode + prefix + "-" + suffix
}
extension String.CharacterView {
/// This method makes it easier extract a substring by character index where a character is viewed as a human-readable character (grapheme cluster).
internal func substring(start: Int, offsetBy: Int) -> String? {
guard let substringStartIndex = self.index(startIndex, offsetBy: start, limitedBy: endIndex) else {
return nil
}
guard let substringEndIndex = self.index(startIndex, offsetBy: start + offsetBy, limitedBy: endIndex) else {
return nil
}
return String(self[substringStartIndex ..< substringEndIndex])
}
}
Example
func testFormat(sourcePhoneNumber: String) -> String {
if let formattedPhoneNumber = format(phoneNumber: sourcePhoneNumber) {
return "'\(sourcePhoneNumber)' => '\(formattedPhoneNumber)'"
}
else {
return "'\(sourcePhoneNumber)' => nil"
}
}
print(testFormat(sourcePhoneNumber: "1 800 222 3333"))
print(testFormat(sourcePhoneNumber: "18002223333"))
print(testFormat(sourcePhoneNumber: "8002223333"))
print(testFormat(sourcePhoneNumber: "2223333"))
print(testFormat(sourcePhoneNumber: "18002223333444"))
print(testFormat(sourcePhoneNumber: "Letters8002223333"))
print(testFormat(sourcePhoneNumber: "1112223333"))
Example Output
'1 800 222 3333' => '1 (800) 222-3333'
'18002223333' => '1 (800) 222-3333'
'8002223333' => '(800) 222-3333'
'2223333' => '222-3333'
'18002223333444' => nil
'Letters8002223333' => '(800) 222-3333'
'1112223333' => nil
Really simple solution:
extension String {
func applyPatternOnNumbers(pattern: String, replacementCharacter: Character) -> String {
var pureNumber = self.replacingOccurrences( of: "[^0-9]", with: "", options: .regularExpression)
for index in 0 ..< pattern.count {
guard index < pureNumber.count else { return pureNumber }
let stringIndex = String.Index(utf16Offset: index, in: pattern)
let patternCharacter = pattern[stringIndex]
guard patternCharacter != replacementCharacter else { continue }
pureNumber.insert(patternCharacter, at: stringIndex)
}
return pureNumber
}
}
Usage:
guard let text = textField.text else { return }
textField.text = text.applyPatternOnNumbers(pattern: "+# (###) ###-####", replacmentCharacter: "#")
Masked number typing
/// mask example: `+X (XXX) XXX-XXXX`
func format(with mask: String, phone: String) -> String {
let numbers = phone.replacingOccurrences(of: "[^0-9]", with: "", options: .regularExpression)
var result = ""
var index = numbers.startIndex // numbers iterator
// iterate over the mask characters until the iterator of numbers ends
for ch in mask where index < numbers.endIndex {
if ch == "X" {
// mask requires a number in this place, so take the next one
result.append(numbers[index])
// move numbers iterator to the next index
index = numbers.index(after: index)
} else {
result.append(ch) // just append a mask character
}
}
return result
}
Call the above function from the UITextField delegate method:
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
guard let text = textField.text else { return false }
let newString = (text as NSString).replacingCharacters(in: range, with: string)
textField.text = format(with: "+X (XXX) XXX-XXXX", phone: newString)
return false
}
So, that works better.
"" => ""
"0" => "+0"
"412" => "+4 (12"
"12345678901" => "+1 (234) 567-8901"
"a1_b2-c3=d4 e5&f6|g7h8" => "+1 (234) 567-8"