I'm attempting to test user input for a function without using the try/catch method. I need to test the String input to be both > 0 and also test that it is an integer. Is there any advice on how to implement this?
Thank you.
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Once you've checked if it's an integer, checking if it's greater than zero is trivial. Checking whether it's an integer is a solved problem.Green Cloak Guy– Green Cloak Guy2021-06-30 17:27:15 +00:00Commented Jun 30, 2021 at 17:27
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if your string has only digits, it's certainly a positive integershikida– shikida2021-06-30 17:29:30 +00:00Commented Jun 30, 2021 at 17:29
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Right, but how would i go about checking this? I currently take the input as a String, and then convert using parseInt. But how would i go about checking the string for an integer prior to converting? Obviously the function would fall apart during the conversion if a non-integer was inputted. Thanks!Jack M– Jack M2021-06-30 17:31:38 +00:00Commented Jun 30, 2021 at 17:31
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1 Answer
Use this to check
import java.util.regex.Pattern;
public class NaturalNumberChecker {
public static final Pattern PATTERN = Pattern.compile("[0-9]+");
boolean isNaturalNumber(String input) {
return input != null && PATTERN.matcher(input).matches();
}
}
if wants to handle the case when user may enter integer with spaces use trim method to delete leading and trailing spaces in user input
