Convert Character to Int in Swift 2.0

by

In Swift 2.0, toInt(), etc., have been replaced with initializers. (In this case, Int(someString).)

Because not all strings can be converted to ints, this initializer is failable, which means it returns an optional int (Int?) instead of just an Int. The best thing to do is unwrap this optional using if let.

I’m not sure exactly what you’re going for, but this code works in Swift 2, and accomplishes what I think you’re trying to do:

let unsolved = "123abc"

var fileLines = [Int]()

for i in unsolved.characters {
    let someString = String(i)
    if let someInt = Int(someString) {
        fileLines += [someInt]
    }
    print(i)
}

Or, for a Swiftier solution:

let unsolved = "123abc"

let fileLines = unsolved.characters.filter({ Int(String($0)) != nil }).map({ Int(String($0))! })

// fileLines = [1, 2, 3]

You can shorten this more with flatMap:

let fileLines = unsolved.characters.flatMap { Int(String($0)) }

flatMap returns “an Array containing the non-nil results of mapping transform over self“… so when Int(String($0)) is nil, the result is discarded.

More Related Contents:

  1. Iterate through a String Swift 2.0
  2. Overriding methods in Swift extensions
  3. Swift: guard let vs if let
  4. Return instancetype in Swift
  5. Swift 2 – UnsafeMutablePointer to object
  6. Deinit method is never called – Swift playground
  7. Swift do-try-catch syntax
  8. What protocol should be adopted by a Type for a generic function to take any number type as an argument in Swift?
  9. The “++” and “–” operators have been deprecated Xcode 7.3
  10. Differences in NSDateComponents syntax?
  11. How to round a Double to the nearest Int in swift?
  12. Get integer value from string in swift
  13. Is it possible to replicate Swifts automatic numeric value bridging to Foundation (NSNumber) for (U)Int8/16/32/64 types?
  14. Fix warning “C-style for Statement is deprecated” in Swift 3
  15. fatal error: swapping a location with itself is not supported with Swift 2.0
  16. Why is Equatable not defined for optional arrays
  17. Selecting global or object print function
  18. Get nth character of a string in Swift
  19. What’s the simplest way to convert from a single character String to an ASCII value in Swift?
  20. Swift 2.0 : ‘enumerate’ is unavailable: call the ‘enumerate()’ method on the sequence
  21. Any reason not use use a singleton “variable” in Swift?
  22. How to convert an Int to a Character in Swift
  23. Convert Swift Array to Dictionary with indexes [duplicate]
  24. In Swift 3, how to calculate the factorial when the result becomes too high? [duplicate]
  25. How do you enumerate OptionSetType in Swift?
  26. Swift playground – How to convert a string with comma to a string with decimal
  27. what are the rules for spaces in swift
  28. Class ‘ViewController’ has no initializers in swift
  29. Whats the Swift animate WithDuration syntax?
  30. How to convert a binary to decimal in Swift?

Leave a Comment