这是我的代码
import java.util.Random;
import javax.swing.JOptionPane;
public class randomnumbersv2 {
public static void main(String[] args){
Double randomnumber = Double.parseDouble(JOptionPane.showInputDialog("Please enter the maximum number that you would like this program to generate"));
Random rnd = new Random();
System.out.println(rnd.nextInt(How would I make sure that what is eneted in the Joption can be put into here)); // change int to whatever number you want, this number will be the max random number generated
JOptionPane.showMessageDialog(null, "Your random number is" + randomnumber);
}
}
答案 0 :(得分:2)
Random#nextInt接受一个整数值作为其上限。因此输入的值应该是这样的。另外,根据文档,数字应为正数:
try {
int maxNumber =
Integer.parseInt(JOptionPane.showInputDialog("Please enter input"));
if (maxNumber > 0) {
Random rnd = new Random();
System.out.println(rnd.nextInt(maxNumber));
} else {
throw new IllegalArgumentException("Non positive number not allowed");
}
} catch (NumberFormatException e) {
throw new IllegalArgumentException("Invalid integer", e);
}