Question

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

Answer 1

fun toFloat(input: String): Double {
    val commaCount = input.count { it == ',' }
    val dotCount = input.count { it == '.' }

    val lastComma = input.lastIndexOf(',')
    val lastDot = input.lastIndexOf('.')

    var str = input

    if (commaCount > 0 && dotCount > 0) {
        str = if (lastComma > lastDot) {
            str.replace(".", "").replace(",", ".")
        } else {
            str.replace(",", "")
        }
    } else if (commaCount > 0) {
        str = str.replace(".", "").replace(",", ".")
    } else {
        str = str.replace(",", "")
    }

    return str.toDouble()
}

fun main() {
    println(String.format("%.3f", toFloat("1,224,533.533")))
    println(String.format("%.3f", toFloat("1.224.533,533")))
    println(String.format("%.2f", toFloat("2.354,67")))
    println(String.format("%.2f", toFloat("2,354.67")))
}

 
  
/*
run:
  
1224533.533
1224533.533
2354.67
2354.67

*/

 

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Answer 2

fun toFloat(input: String): Double {
    val commaCount = input.count { it == ',' }
    val dotCount = input.count { it == '.' }

    val lastComma = input.lastIndexOf(',')
    val lastDot = input.lastIndexOf('.')

    var str = input

    if (commaCount > 0 && dotCount > 0) {
        // Both separators exist
        str = if (lastComma > lastDot) {
            str.replace(".", "").replace(",", ".")
        } else {
            str.replace(",", "")
        }
    } else if (commaCount > 1 && dotCount == 0) {
        // All commas: assume last one is decimal
        val last = str.lastIndexOf(',')
        str = str.removeRange(last, last + 1).replace(",", "")
        str = str.substring(0, last) + "." + str.substring(last)
    } else if (dotCount > 1 && commaCount == 0) {
        // All dots: assume last one is decimal
        val last = str.lastIndexOf('.')
        str = str.removeRange(last, last + 1).replace(".", "")
        str = str.substring(0, last) + "." + str.substring(last)
    } else if (commaCount > 0) {
        str = str.replace(".", "").replace(",", ".")
    } else {
        str = str.replace(",", "")
    }

    return str.toDouble()
}

fun main() {
    println(String.format("%.3f", toFloat("1,224,533.533"))) 
    println(String.format("%.3f", toFloat("1.224.533,533"))) 
    println(String.format("%.2f", toFloat("2.354,67")))     
    println(String.format("%.2f", toFloat("2,354.67")))      
    println(String.format("%.2f", toFloat("2,354,67")))     
    println(String.format("%.2f", toFloat("2.354.67")))     
}

 
  
/*
run:
  
1224533.533
1224533.533
2354.67
2354.67
23546.70
23546.70

*/

 

70+ SQL courses for beginners and professionals