Question

How to convert a string with either, or . as decimal/thousand separators into a float in Swift

Answer 1

import Foundation

func toFloat(_ input: String) -> Double {
    let commaCount = input.filter { $0 == "," }.count
    let dotCount = input.filter { $0 == "." }.count

    let lastComma = input.lastIndex(of: ",")?.utf16Offset(in: input) ?? -1
    let lastDot = input.lastIndex(of: ".")?.utf16Offset(in: input) ?? -1

    var str = input

    if commaCount > 0 && dotCount > 0 {
        if lastComma > lastDot {
            str = str.replacingOccurrences(of: ".", with: "")
            str = str.replacingOccurrences(of: ",", with: ".")
        } else {
            str = str.replacingOccurrences(of: ",", with: "")
        }
    } else if commaCount > 0 {
        str = str.replacingOccurrences(of: ".", with: "")
        str = str.replacingOccurrences(of: ",", with: ".")
    } else {
        str = str.replacingOccurrences(of: ",", with: "")
    }

    return Double(str) ?? 0.0
}

print(String(format: "%.3f", toFloat("1,224,533.533")))
print(String(format: "%.3f", toFloat("1.224.533,533")))
print(String(format: "%.2f", toFloat("2.354,67")))
print(String(format: "%.2f", toFloat("2,354.67")))



/*
run:

1224533.533
1224533.533
2354.67
2354.67

*/

 

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