Error: incompatible types: possible lossy conversion from double to in [duplicate]

Question

I'm trying to print the start value with the conversion but I'm getting this error:

error: incompatible types: possible lossy conversion from double to int
        int zeile = Programm.printTable(10.0, 1000.0, 50);

This is my code

public class miles {
    
    public static double km2meilen(double entfernung) {
        return (entfernung / 1.852);
    }

    public static double meilen2km(double entfernung) {
        return ((double) entfernung * 1.852);
    }

    public static double printTable(double start, double end, double step) {
        System.out.printf("\n km Seemeilen Seemeilen km");
        double y = 0.0;
        for (; start <= end; start += end) {
            double x = 0.0;
            System.out.printf("\n%10.2f %10.2f %10.2f %10.2f", (double) start, (double) km2meilen(start), (double) start, (double) meilen2km(start));
            x = x + 1.0;
            return x;
        }
    }

    public static void main(String[] args) {
        printTable(0.0, 50.0, 1000.0);
    }
}

Answer 1

The printTable method returns a double so you may save it in a double, or explicitly cast it

double zeile = Programm.printTable(10.0, 1000.0, 50);

int zeile = (int) Programm.printTable(10.0, 1000.0, 50);

---

Then, your conversion methods don't need any cast

public static double km2meilen(double entfernung) {
    return entfernung / 1.852;
}
public static double meilen2km(double entfernung) {
    return entfernung * 1.852;
}

And your printTable doesn't define x where it should, and doesn't return it where it should, and has useless casting too

public static double printTable(double start, double end, double step) {
    System.out.printf("\n%10s %10s %10s %10s", "km", "Seemeilen", "Seemeilen", "km");
    double y = 0.0;
    double x = 0.0;
    for (; start <= end; start += step) {
        System.out.printf("\n%10.2f %10.2f %10.2f %10.2f", start, km2meilen(start), start, meilen2km(start));
        x = x + 1.0;
    }
    return x;
}

        km  Seemeilen  Seemeilen         km
     10,00       5,40      10,00      18,52
     60,00      32,40      60,00     111,12
    110,00      59,40     110,00     203,72
    160,00      86,39     160,00     296,32
    210,00     113,39     210,00     388,92
    260,00     140,39     260,00     481,52
    310,00     167,39     310,00     574,12
    360,00     194,38     360,00     666,72
    410,00     221,38     410,00     759,32
    460,00     248,38     460,00     851,92
    510,00     275,38     510,00     944,52
    560,00     302,38     560,00    1037,12
    610,00     329,37     610,00    1129,72
    660,00     356,37     660,00    1222,32
    710,00     383,37     710,00    1314,92
    760,00     410,37     760,00    1407,52
    810,00     437,37     810,00    1500,12
    860,00     464,36     860,00    1592,72
    910,00     491,36     910,00    1685,32
    960,00     518,36     960,00    1777,92

Answer 2

Conversion might be issue, you can type case it as mentioned below , moreover, printTable is giving compilation error, you might need to put return outside of for loop.

int zeile = (int)Programm.printTable(10.0, 1000.0, 50);