问只删除字符串中句子开头的数字- Swift

EN

let string = """
    1There were 101 dalmatians in the room. 2 They had 2 parents.
    3 The parents were named Pongo and Perdita.
    """

var result: String = ""
string.enumerateSubstrings(in: string.startIndex..., options: .bySentences) { substring, _, _, _ in
    guard
        let trimmed = substring?.replacingOccurrences(of: #"^\d+\s*"#, with: "", options: .regularExpression)
    else { return }
    result.append(trimmed)
}
print(result)

var checkForDigit = true // State of loop
var digitFound = false // Need this to ignore space after digit 
var output = ""
for character in text {
    if character.isPunctuation {
        output.append(character)
        checkForDigit = true
        continue
    }

    if checkForDigit {
        if !character.isNumber {
            if digitFound && character.isWhitespace {
                continue
            }
            output.append(character)
            if !character.isWhitespace {
                checkForDigit = false
            }
        } else {
            digitFound = true
        }
        continue
    }
    digitFound = false
    output.append(character)
}

extension Bool {
    var negated: Bool { !self }
}

var string = """
1There were 101 dalmatians in the room. 2 They had 2 parents.
3 The parents were named Pongo and Perdita.
"""
var ranges: [Range<String.Index>] = []

string.enumerateSubstrings(in: string.startIndex..., options: .bySentences) { _, range, _, _ in
    ranges.append(range)
}

for range in ranges.reversed() {
    string.replaceSubrange(range, with: string[range].drop(while: \.isLetter.negated))
}

string  // "There were 101 dalmatians in the room. They had 2 parents.\nThe parents were named Pongo and Perdita."