CODEWITHSUNDEEP
javaalgorithminteger
user3466314
user3466314

Reputation: 37

How do I make sure User input integer type only and integer that is greater than 0?

I am attempting to make sure the user input int type only and make sure the integer inputted is greater than 0.

I was able to come up with the following to make sure the input is int type:

Scanner scan = new Scanner(System.in);
while(!scanner.hasNextInt()) 
{
    scanner.next();
}
int input = scan.nextInt();

But how should I include a condition checking to make sure the integer is greater than 0 as well?

Upvotes: 0

Views: 6729

Answers (4)

Zeshan Khan
Zeshan Khan

Reputation: 294

You may use a condition in your code but not in the loop as. `

Scanner scan = new Scanner(System.in);
abc: 
while(!scanner.hasNextInt()) 
{
    scanner.next();
}
int input = scan.nextInt();
if(input <= 0){
   goto abc;
}

`

Upvotes: 0

user3229557
user3229557

Reputation:

put an if statement inside your while loop like this

if(num <= 0){
   System.out.println("Enter a number greater than zero");
}
else{
   break;
}

Upvotes: 0

MadProgrammer
MadProgrammer

Reputation: 347332

The problem with your current approach is you've already ready the value from the Scanner before it reaches int input = scan.nextInt();, meaning that by the time you use nextInt, there's nothing in the Scanner to be read and it will wait for the next input from user...

Instead, you could read the String from the Scanner using next, use Integer.parseInt to try and parse the result to an int and then check the result, for example...

Scanner scanner = new Scanner(System.in);
int intValue = -1;
do {
    System.out.print("Please enter a integer value greater than 0: ");
    String next = scanner.next();
    try {
        intValue = Integer.parseInt(next);
    } catch (NumberFormatException exp) {
    }
} while (intValue < 0);

System.out.println("You input " + intValue);

Upvotes: 2

joe
joe

Reputation: 29

using .isDigit() method then checking to see if that number is greater than 0 if it is a digit

Upvotes: -1

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