Question

进行无效输入后，无效的输入循环将继续出现在此程序中。我正在寻求继续询问用户输入，直到他/她输入有效数据。然后我想使用该输入继续该程序。我很肯定有一种与此相关的循环。谢谢你的帮助。

identInput = JOptionPane.showInputDialog(null, "Please enter a student ID: ");
intID = Integer.parseInt(identInput);
savedIntID = Integer.parseInt(identInput);

for(x = 0; x < studentIDs.length; ++x)
{
    if(identInput.equals(studentIDs[x]))
    {
        JOptionPane.showMessageDialog(null, "The first name associated with \nStudent ID "
                + intID + " is: " + firstNames[x] + "\n" + firstNames[x] + "'s current GPA is: "
                + gPAs[x]);

        inputTruth = true;
        break;
    }
}

//The following will show up and continue to if the data is incorrect. Am not
//sure how to reuse if good data are entered.

while(inputTruth == false)
{
    JOptionPane.showInputDialog(null, "The Student ID you entered "
            + savedIntID + "\nis not valid. \nPlease enter another Student ID: ");
}

Answer 1

你只需要一个循环

while(!isInputValid){
 //Take your input
 if(check == input){
   isInputValid = true;
 }else{
  //Please enter valid input try again.
 }
}

Answer 2

inputTruth = false;
while(inputTruth == false)
{
identInput = JOptionPane.showInputDialog(null, "Please enter a student ID: ");
intID = Integer.parseInt(identInput);
savedIntID = Integer.parseInt(identInput);

for(x = 0; x < studentIDs.length; ++x)
{
    if(identInput.equals(studentIDs[x]))
    {
        JOptionPane.showMessageDialog(null, "The first name associated with \nStudent ID "
                + intID + " is: " + firstNames[x] + "\n" + firstNames[x] + "'s current GPA is: "
                + gPAs[x]);

        inputTruth = true;
        break;
    }
}

//The following will show up and continue to if the data is incorrect. Am not
//sure how to reuse if good data are entered.

if(inputTruth == false)
{
    JOptionPane.showInputDialog(null, "The Student ID you entered "
            + savedIntID + "\nis not valid. \nPlease enter another Student ID: ");
}
}

Answer 3

这是你想要的吗？

inputTruth = false;

while(inputTruth == false)
{
  for(x = 0; x < studentIDs.length; ++x)
  {     
    if(identInput.equals(studentIDs[x]))
    {
     JOptionPane.showMessageDialog(null, "The first name associated with \nStudent ID "
       + intID + " is: " + firstNames[x] + "\n" + firstNames[x] + "'s current GPA is: " 
       + gPAs[x]);

     inputTruth = true;
     break;
   }
 }
 if (inputTruth == false) {
 identInput = JOptionPane.showInputDialog(null, "The Student ID you entered " 
  + savedIntID + "\nis not valid. \nPlease enter another Student ID: ");
  }
}

Java：无效输入后重新运行程序中的用户输入（循环？）

3 个答案: