Preventing errors when typing a letter into a String

[doymand]

I would like general guidance on how to avoid an error when someone tries to type a letter into an integer from the scanner class. My program asks for a number, but if someone types a letter in it gives multiple errors and I would like to know how to avoid this.

I think I would use a try, catch, but I am not exactly sure how to implement that. What error do I put in the catch? Can I just use one statement for all errors?

I was thinking something like this

try{
x = scanner.nextInt}

catch(Exception x){
}

What do I put in the spot where I have exception?

[al_Marshy_1981]

Validate if a String contains only numbers - A Java Code Example

[joshdgreen]

You could try something like:

String example = "12a";
try
{
     int temp = Integer.parseInt(example);
}
catch(NumberFormatException e)
{
     System.out.print(e);
}

In short, it tries to convert your string to an integer number. If it can't then it will throw an error meaning your string is not a number.

[Honopac]

Here is what you need:

Scanner scan = new Scanner(System.in);
int number = 0;

System.out.print("Enter a number: ");

try
{
number = scan.nextInt();
}
catch(InputMismatchException e)
{
System.out.println("A Non-numeric data was entered");
System.exit(0);
}

System.out.println(number);

[joshdgreen]

Honopac, at least let them try to figure it out...

[Honopac]

Next time I will try to give them just a hint, but not the actual code. This is the best way to help them learn how to solve programming problems on their own.