CODEWITHSUNDEEP
iosswift3
Brewski
Brewski

Reputation: 684

Remove empty decimal with .droplast() in swift 3

I'm trying to remove empty trailing decimals and instead of using an extension for float I want to consider using droplast() if the result has any trailing zeros:

            if result.contains(".0") {
                result.characters.dropLast()
            }

            if result.contains(".00") {
                result.characters.dropLast(2)
            }

This does not seem to work and I get the warning:

Result of call to 'droplast()' is unused

Upvotes: 1

Views: 536

Answers (2)

vadian
vadian

Reputation: 285092

Alternative solution using regular expression, the number of decimal places doesn't matter:

var result = "1.00"
result = result.replacingOccurrences(of: "\\.0+$", 
                          with: "", 
                       options: .regularExpression, 
                         range: result.startIndex..<result.endIndex)

Considering the entire string you can even omit the range parameter:

result = result.replacingOccurrences(of: "\\.0+$", 
                          with: "", 
                       options: .regularExpression)

Upvotes: 3

Wilson
Wilson

Reputation: 9136

dropLast method will return a subsequence that leaves off the dropped items, so in this case it won't modify the result variable, then you would need to create a new String based on the result of dropLast method call and assign it to result variable.

var result: String = "1.00"
var dropCount = getTrailingDecimalCount(from: result)
print(dropCount) // outputs 2

if let dropCount = dropCount {
  result = String(result.characters.dropLast(dropCount))
  print(result) // outputs 1.
}

func getTrailingDecimalCount(from string: String) -> Int? {
  var counter = 0

  guard string.characters.contains(".") else {
    return nil
  }

  for char in string.characters.reversed() {
    if char == "." {
      break
    }

    counter = counter + 1
  }

  return counter
}

Upvotes: 1

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