这里一些帮助是我的代码:需要在Java方法showMessageDialog
//DebugTwo4.java
import javax.swing.JOptionPane;
public class DebugTwo4
{
public static void main(String[] args)
{
String costString;
double cost;
double tax = 0.06;
costString = JOptionPane.showInputDialog(null,
"Enter price of item you are buying", "Purchases",
JOptionPane.INFORMATION_MESSAGE);
cost = Double.parseDouble("cost");
JOptionPane.showMessageDialog(null,"With " + tax * 100 + "% tax, purchase is $" + cost + cost * tax);
System.exit(0);
}
}
和错误信息是: 异常线程“main” java.lang.NumberFormatException:对于输入字符串:“成本” 在sun.misc.FloatingDecimal.readJavaFormatString(FloatingDecimal.java:1241) 在java.lang.Double.parseDouble(Double.java:540) 在DebugTwo4.main(DebugTwo4.java:16)
'成本= Double.parseDouble (“成本”);''双重'检查该行。 –
@ user2731240“成本”是字符串值而不是变量。 – gjman2