Question

我正在尝试为我所在的编程类创建一个计算器，它包含用户输入然后进行数学运算。我选择使用JOptionPane作为此赋值的用户输入部分，一切顺利，直到我要求Java在JOptionPane消息对话框中将字符串与一些先前定义的变量连接起来。我正在使用DrJava。

我收到错误：

Error: unexpected type
  required: class
  found:    value

这是我的代码：

(Line 1) JOptionPane.showMessageDialog(null, "Thank you! Here are your results:\n"+

(2)               "The addition of "+fnum+" and "+snum+" is "(fnum+snum)"\n"+

(3)               "The subtraction of "+fnum+" and "+snum+" is "+(5-3));

我在第二行收到错误，我的光标位于fnum和+之间（fnum + snum）

已定义变量，并且此过程使用System.out.println方法正常工作。

有关正在发生的事情的任何建议？

Answer 1

OptionPane.showMessageDialog(null, "Thank you! Here are your results:\n"+
"The addition of "+fnum+" and "+snum+" is "+(fnum+snum)+"\n"+
"The subtraction of "+fnum+" and "+snum+" is "+(5-3));

Answer 2

这一行是罪魁祸首，

(2) "The addition of "+fnum+" and "+snum+" is "(fnum+snum)"\n"+

而不是使用此

(2) "The addition of "+fnum+" and "+snum+" is "+(fnum+snum)+"\n"+

带字符串和变量连接的JOptionPane错误

2 个答案: