条件语句不起作用Java

Question

int number;
  int randomNum1= (int)(Math.random() * 12 + 1);
 int randomNum2= (int)(Math.random() * 12 + 1);
    try{
        number = Integer.parseInt(this.txtInput.getText());
    }
    catch (Exception e){
        JOptionPane.showMessageDialog(this, "Please input a integer.", "Error",
                JOptionPane.ERROR_MESSAGE);
        return;
        }                
    if (number > randomNum1 && number < randomNum2 ||  number > randomNum2 && number  < randomNum1){
    lblRand1.setText(Integer.toString(randomNum1));
    lblRand2.setText(Integer.toString(randomNum2));
    lblOutput.setText("YOU WIN.");
    }else
    lblRand1.setText(Integer.toString(randomNum1));
    lblRand2.setText(Integer.toString(randomNum2));
    lblOutput.setText("YOU LOSE.");

why does it always display you lose even my input is a number that must win?

Answer 1

You forgot {} for else thats why Lose statement is always executed.

• Thats why the only statement in else block is lblRand1.setText(Integer.toString(randomNum1));
• After that, program will flow normally to execute lblOutput.setText("YOU LOSE.");
• Hence, even if your if condition is true and label is set with You Win , lblOutput.setTest("You Lost") is executed as result of normal program execution as it is not in else block

Change

else
lblRand1.setText(Integer.toString(randomNum1));
lblRand2.setText(Integer.toString(randomNum2));
lblOutput.setText("YOU LOSE.");

to

else{

lblRand1.setText(Integer.toString(randomNum1));
    lblRand2.setText(Integer.toString(randomNum2));
    lblOutput.setText("YOU LOSE.");
}

Answer 2

Never use statements without curly braces (see your else !)

if ([...]){
  ...
}else
lblRand1.setText(Integer.toString(randomNum1));
lblRand2.setText(Integer.toString(randomNum2));
lblOutput.setText("YOU LOSE.");

is equivalent to

if ([...]){
  ...
} else {
  lblRand1.setText(Integer.toString(randomNum1));
}
lblRand2.setText(Integer.toString(randomNum2));
lblOutput.setText("YOU LOSE.");

Answer 3

You forgot the block for the else.

Besides you can use Math.max and Math.min to simplify your condition

lblRand1.setText(Integer.toString(randomNum1));
lblRand2.setText(Integer.toString(randomNum2));
if (number > Math.min(randomNum1, randomNum2) 
    && number < Math.max(randomNum1, randomNum2)){
    lblOutput.setText("YOU WIN.");
} else {
    lblOutput.setText("YOU LOSE.");
}