fun replaceFloatDigit(number: Double, position: Int, newDigit: Char): Double {
// Validate that newDigit is indeed a single digit
require(newDigit.isDigit()) { "Replacement must be a digit (0-9)." }
// Convert number to string with fixed precision (10 decimal places)
val strNum = String.format("%.10f", number)
// Validate position
if (position < 0 || position >= strNum.length) {
throw IndexOutOfBoundsException("Position is out of range for the number string.")
}
// Ensure position points to a digit
if (strNum[position] == '.' || strNum[position] == '-') {
throw IllegalArgumentException("Position points to a non-digit character.")
}
// Replace digit (strings are immutable, so build a new one)
val modified = StringBuilder(strNum).apply {
setCharAt(position, newDigit)
}.toString()
// Convert back to Double
return modified.toDouble()
}
fun main() {
try {
val num = 89710.291
val pos = 2 // 0-based index
val newDigit = '8'
val result = replaceFloatDigit(num, pos, newDigit)
// Print result with 3 decimal places
println("Modified number: %.3f".format(result))
} catch (e: Exception) {
println("Error: ${e.message}")
}
}
/*
run:
Modified number: 89810.291
*/
