如果我将2的double数据类型值相加，结果将四舍五入并打印出来。如何获得double的确切输出？

Question

I need to add double values and display it result. But the resulting value was wrong.

class Program
{
    static void Main(string[] args)
    {
        int i = 4;
        double d = 4.0;
        string s = "HackerRank ";
        int i1 = 12;
        double d1 = 4.0;
        string s1 = "is the best place to learn and practice coding!";
        int sum = 0; string s2 = string.Empty;
        sum = sum+i + i1;
        s2 = s2 + s + s1;
        Console.WriteLine(sum);
        Console.WriteLine("{0}+{1}={2}",d,d1,(d+d1).ToString());
        Console.WriteLine(s2);
        Console.ReadLine();
    }
}

the output snapshot is here

My expected output is 4.0+4.0=8.0

But the output value is roundoff. Can anyone provide the reason and solution for this question?

Answer 1

尝试这个

Console.WriteLine( String.Format("{0:0.0}", d + d2));

Answer 2

在每个double上尝试使用ToString()

Console.WriteLine($"{d.ToString("G1")}+{d1.ToString("G1")}=(d + d1).ToString("G1")});

Answer 3

如果要以x.xx格式显示输出，可以使用：

Console.WriteLine("{0:F2}+{1:F2}={2:F2}",d,d1,d+d1);

Answer 4

Use this

Console.WriteLine("{0:F}+{1:F}={2:F}",d,d1,d+d1);

"F" is Fixed-Point Format Specifier. You can also specify the desired number of decimal places by changing the "F" to "F2,F3 and so on" as per your requirement or leave it as "F" so that it can return output according to the variable.