如何解决 java.lang.NumberFormatException：对于输入字符串：“TooLow”

Question

I am trying to create a set of code that allows you to play guess the number with the computer. The problem section and the debugging console section are both clear and I was able to run it until I tried to input values through the intergrated terminal.

I have converted the returned string value from Input.nextLine() to an int value although that seemed to have no effect, I also switched from running the code on the intergrated terminal instead of the debugging console. In addition, I tried the catch(NumberFormatException) statement but it failed as Visual Studio Code can't identify catch nor NumberFormatException.

while ( win == false)
     {
int CorrectNumber = 70;
int g = (int)( Math.random() * 101 );
System.out.print( "The Number I Guess Is:" + g);

String TooHigh = "TooHigh";
//type TooHigh if the number computer guessed is too high 

TooHigh = input.nextLine();
int h1 = Integer.parseInt(TooHigh);

String TooLow = "TooLow";
//type TooLow if the number computer guessed is too low

TooLow = input.nextLine();
int l1 = Integer.parseInt(TooLow);

if ( g == h1 ) //too high
{
    int y = (int)( Math.random() * ( g - 70 ) );
    System.out.print( "Another Number I Guessed is: " + y );
}
else if ( g == l1 ) //too low
{
    int z = (int)( Math.random() * ( 70 - g ) );
    System.out.print( "Another Number I Guessed is: " + z );
}
else if ( g == 70 ) //computer wins
{
    win = true;
}

When I input words to tell the computer whether or not the number it guessed is too high or too low, I expect it giving me another number. But instead, I get the following messages:

    Exception in thread "main" java.lang.NumberFormatException: For input string: "TooLow" 
at java.base/java.lang.NumberFormatException.forInputString(NumberFormatException.java:65)
            at java.base/java.lang.Integer.parseInt(Integer.java:652)
            at java.base/java.lang.Integer.parseInt(Integer.java:770)
            at RevGuess.main(RevGuess.java:23)

Answer 1

Why are you trying to get an int from the String that is for telling that the guess was too low? That can just be treated as a String and then you can compare Strings with.equals to see if the Strings' values are the same. If they are, you tell the program that it is too low or to high.

Answer 2

You are comparing int with a String that is why you are getting the error. What you should do is compare the user input with toohigh or toolow and execute the too low or too high portion of your if/else depending on the user input

Answer 3

Base on your source code, java can not convert word "TooLow" to integer. it is still bias about your goal, if you want to compare integer always input number, so the code int h1 = Integer.parseInt(TooHigh); will work perfectly.