如何将一个Double型数据转换成字符串并截取字符串截取小数点后面0的方法

要求:

不要四舍五入，
如果没有小数位,将小数点后面的.0改成.00(比如2转换成2.00,而不是2.0)
不知道会有多少位小数,有多少位显示多少位

我想要达到的结果

比如这种的
88.495000
将后面的0给去掉
要是88.495236
就不用去掉

如果是六个0就保留小数点后两位
比如
100.000000
改成
100.00

这是C++实现代码，你可以参考一下

#include <iostream>
#include <algorithm>

using namespace std;

string truncate_tail_zeros(const string &str)
{
    if (str.find_first_of('.') == string::npos)
        return str + ".00";
    string r;
    auto itr = find_if(str.rbegin(), str.rend(), [](auto c)
                       { return c != '0'; });
    reverse_copy(itr, str.rend(), back_inserter(r));
    if (*itr == '.')
        r += "00";
    return r;
}

int main()
{
    string str;
    while (cin >> str)
        cout << "=> " << truncate_tail_zeros(str) << endl;
    return 0;
}

$ g++ -Wall main.cpp
$ ./a.out
100
=> 100.00
100.0
=> 100.00
100.000 
=> 100.00
100.0012345600
=> 100.00123456

class Test{
    public static String getFormatNumber(Double a){
        BigDecimal bigDecimal = new BigDecimal(new DecimalFormat("##.00").format(a));
        if(a == bigDecimal.doubleValue()){
            return bigDecimal.toString();
        }
        return a.toString();
    }
 
    public static void main(String[] args) {
        System.out.println(getFormatNumber(2.00d));
        System.out.println(getFormatNumber(2.12321300));
        System.out.println(getFormatNumber(88.2324));
        System.out.println(getFormatNumber(88.0000));
    }

企业微信截图_adca1407-4e8c-451d-96cc-34a9667dfd0c.png
有什么问题可以留言

import java.util.Scanner;

public class test {
    public static String work(Double num) {
        String str = num.toString();
        int flag = str.indexOf('.');
        if (flag == -1)
            return str + ".00";
        else
            str += "00";
        int i = str.length() - 1;
        while (i > flag + 2 && str.charAt(i) == '0')
            i--;
        return str.substring(0, i + 1);
    }

    public static void main(String[] args) {
        Double t;
        Scanner sc = new Scanner(System.in);
        t = sc.nextDouble();
        System.out.println(test.work(t));
        sc.close();
    }

}

import java.util.Scanner;

public class My {
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
Double shuju=sc.nextDouble();
String sj=shuju+"";
System.out.println(sj);
int num=sj.indexOf('.')+1;
String result=sj.substring(0, num);
System.out.println(result);
String temp="";
for(int i=sj.length()-1;i>=num;i--) {
if('0'==sj.charAt(i)) {
if(i-num==1) {
result+=sj.substring(num, i+1);
break;
}
}else {
result+=sj.substring(num, i+1);break;
}
}
System.out.println(result);
}
}

这个是对的
import java.util.Scanner;

public class My {
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
Double shuju=sc.nextDouble();
String sj=shuju+"00000";
int num=sj.indexOf('.')+1;
String result=sj.substring(0, num);
String temp="";
for(int i=sj.length()-1;i>=num;i--) {
if('0'==sj.charAt(i)) {
if(i-num==1) {
result+=sj.substring(num, i+1);
break;
}
}else {
result+=sj.substring(num, i+1);break;
}
}
System.out.println(result);
}
}

 
import java.text.DecimalFormat;
 
public class Test2 {
    public static void main(String[] args) {
        Double number = 46.017700;       //这里修改数字
        DecimalFormat dd = new DecimalFormat("#.000000");
        String result = dd.format(number);
        int d = getIndex(result);
        System.out.println(deleteString(result,d));
    }
 
    public static int getIndex(String s){
        int index = 999;
 
        for (int i = s.length()-1; i > 0; i--) {
            String lastNum = String.valueOf(s.charAt(i)); //从末尾开始
            if (lastNum.equals("0")){ //末尾为0
                index = Math.min(index,i);  //记录最小index
            }else if (lastNum.equals(".")){  //6位全是0
                    return -1;
            }else if (!lastNum.equals("0")) {
                return index;
            }
        }
        return index;
    }
 
    public static String deleteString(String str, int index ){
        if (index == 999){
            return str;
        }
        if (index == -1){
            double result = Double.parseDouble(str);
            return new DecimalFormat("#.00").format(result);
        }
        String delStr = "";
        for (int i = 0; i < str.length(); i++) {
            if(i != index){
                delStr += str.charAt(i);
            }
            else break;
        }
        return delStr;
    }
}

这个题主一个问题重复问多次，是刷回答问题的？

都对

https://ask.csdn.net/questions/7642079?spm=1005.2026.3001.5635&utm_medium=distribute.pc_relevant_ask_down.none-task-ask-2~default~OPENSEARCH~Rate-1.pc_feed_download_top3ask&depth_1-utm_source=distribute.pc_relevant_ask_down.none-task-ask-2~default~OPENSEARCH~Rate-1.pc_feed_download_top3ask

 
public static String wrok(String string){
        int i = string.indexOf(".");//寻找小数点
        if(i==-1){
            //没找到,在后面加上.00直接返回
            return string+=".00";
        }else{
            //找到了
            if(string.substring(string.indexOf(".")+1,string.length()).equals("000000")){
                //如果小数后面后面六个是0，那么就替换成00
                string=string.replace("000000","00");
            }else{
                //如果最后一位小数是0,去掉零
                while (string.lastIndexOf("0")==string.length()-1){
                    string=string.substring(0,string.lastIndexOf("0"));
                }
            }
        }
        //返回结果
        return string;
    }

加入这个方法，望采纳

public static void main(String[] args) {

        Double value = 1155.905600;

        DecimalFormat format = new DecimalFormat("0.00");
        BigDecimal bigDecimal = new BigDecimal(format.format(value));

        String output = "";
        output = value.toString();

        if (value == bigDecimal.doubleValue()) {

            output = bigDecimal.toString();

        }

        System.out.println("输出: " + output);
    }

楼上这么多代码，我就想问楼主想用什么语言实现