I am a completely beginner. I have to find the perimeter of a circle. In the description of the task I see that the expected result is shown with decimal point, but when I solve it, I get the result printed with comma, not a dot. What could be the reason and how can I change my output to be with ".", not ",".
You probably have a locale issue. Your system locale is printing the decimal numbers using a comma. Try to use java.text.NumberFormat class in JDK. It allows to change a locale of the output in place.
Your code should look something like this
public static void main(String[] args) {
NumberFormat nf = NumberFormat.getInstance(new Locale("en", "US"));
String val = nf.format(1.03);
System.out.println(val);
}
For more information on various locale specifics of displaying a decimal I would recommend to look at https://en.wikipedia.org/wiki/Decimal_separator. Also getting familiar w the standard java.util.Locale class is recommended