core java. isInteger methods. Finding bug.
public static int isInputInteger(){
@SuppressWarnings("resource")
Scanner input = new Scanner(System.in);
int correctNumber;
while(true){
input.nextLine();
if(input.hasNextInt()){
correctNumber = input.nextInt();
break;
}
else{
System.out.println("Your input isn't integer.Please, try again. ");
}
}
return correctNumber;
}
class PrintFromInput {
protected static int printNumber() {
System.out.printf("Please, enter integer: ");
int intYourConsoleInput = Assert.isInputInteger();
return intYourConsoleInput;
}
}
public class Task {
public static void main(String[] args) {
System.out.println("Congratulation! Your correct integer input is: "+ PrintFromInput.printNumber());
}
}
Inside class Assert there is a method "isInputInteger" everything work but not as I expect :
Session 1
input : f
output: {nothing }
input : f
output : Your input isn't integer.Please, try again.
input: g
output : Your input isn't integer.Please, try again.
input : 3
Congratulation! Your correct integer input is: 3
Session OVER
My question is why there isn't any message after first "f". Please, help me to find bug. Thx in advance !
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I believe OP needs the nextLine() read in order to advance the scanner past the '\n' character after the integer is read. I would simply move it to the end of the while loop instead of at the beginning.
Yes, indeed. I thought the OP would be able to work out the required code move once he sees the result of just deleting it.
That code is wrong in so many ways that it's hard to know where to begin. Let's begin with the first line:
a. your code has the name of a boolean method yet it returns int. Why?
b. in the event of your replying that you misnamed the method then why do you skip a line of input (which could have contained an int)?
a. your code has the name of a boolean method yet it returns int. Why?
b. in the event of your replying that you misnamed the method then why do you skip a line of input (which could have contained an int)?
I think if you just want to get your loop working, you can go along these lines:
while (true){
System.out.println("Input a number");
if(!(scanner.hasNextInt())){System.out.println("Your input isn't integer.Please, try again. ");scanner.next();continue;}
correctNumber = scanner.nextInt();
}
The solution is :
Dear experts thx you so much for your help !
public static int onlyIntegerInput(){
@SuppressWarnings("resource")
Scanner scanner = new Scanner(System.in);
int correctNumber;
while (true){
if(!(scanner.hasNextInt())){
System.out.println("Your input isn't integer. Please, try again. ");
scanner.next();
continue;
}
else{
correctNumber = scanner.nextInt();
break;
}
}
return correctNumber;
}
Dear experts thx you so much for your help !
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