beregning af procent

double procent = (100.0 * antal_rigtige_spg) / antal_spg_ialt;
double procent1ciffer = ((int)(10 * procent)) / 10.0;

Lidt uddybning.

Kode:

using System;

class MainClass
{
    public static void Main(string[] args)
    {
        int n1 = 20;
        int n2 = 30;
        double x = (100.0 * n1) / n2;
        double x1a = ((int)(10 * x)) / 10.0;
        double x1b = ((int)(10 * (x + 0.05))) / 10.0;
        double x1c = Math.Round(x, 1);
        Console.WriteLine("Before rounding " + x);
        Console.WriteLine("Manual round down " + x1a);
        Console.WriteLine("Manual round nearest " + x1b);
        Console.WriteLine("Builtin round nearest " + x1c);
    }
}

Output:

Before rounding 66.6666666666667
Manual round down 66.6
Manual round nearest 66.7
Builtin round nearest 66.7

OK ?

Kanont. Jeg er helt med.

Jeg havde en løsning, som så sådan ud :

double percent = (int)((double)antal_rigtige_spg / antal_spg_ialt*1000+0.5);
int dec = (int)(percent%10);
double result = (int)(percent/10) + dec/10.0;