import java.text.DecimalFormat;
public class ReplaceFloatDigitProgram {
// Function to replace a digit at a given position in a floating-point number
public static double replaceFloatDigit(double number, int position, char newDigit) {
// Validate that newDigit is indeed a digit
if (newDigit < '0' || newDigit > '9') {
throw new IllegalArgumentException("Replacement must be a digit (0-9).");
}
// Convert number to string with fixed precision
DecimalFormat df = new DecimalFormat("0.0000000000"); // 10 decimal places
String strNum = df.format(number);
// Validate position
if (position < 0 || position >= strNum.length()) {
throw new IndexOutOfBoundsException("Position is out of range for the number string.");
}
// Ensure position points to a digit
if (strNum.charAt(position) == '.' || strNum.charAt(position) == '-') {
throw new IllegalArgumentException("Position points to a non-digit character.");
}
// Replace digit
StringBuilder sb = new StringBuilder(strNum);
sb.setCharAt(position, newDigit);
// Convert back to double
return Double.parseDouble(sb.toString());
}
public static void main(String[] args) {
try {
double num = 89710.291;
int pos = 2; // 0-based index
char newDigit = '8';
double result = replaceFloatDigit(num, pos, newDigit);
System.out.printf("Modified number: %.3f%n", result);
} catch (Exception e) {
System.err.println("Error: " + e.getMessage());
}
}
}
/*
run:
Modified number: 89810.291
*/
