java/kotlin:使用固定的总位数设置double/int格式

import java.text.DecimalFormat;

public class NumberFormatter {
    public static void main(String[] args) {
        double number = 12345.6789;
        int totalDigits = 8;

        DecimalFormat df = new DecimalFormat("#." + "#".repeat(totalDigits - 1));
        String formattedNumber = df.format(number);

        System.out.println(formattedNumber);  // 输出: 12345.6789
    }
}

import java.text.DecimalFormat

fun main() {
    val number = 12345.6789
    val totalDigits = 8

    val df = DecimalFormat("#." + "#".repeat(totalDigits - 1))
    val formattedNumber = df.format(number)

    println(formattedNumber)  // 输出: 12345.6789
}