Trying to return user to scanner to re enter a number if value falls out of range (<25)-CodePudding

Im trying to configure my code to tell the user to re enter a number, taking them back to the scanner if it falls outside of my specified range of 25

 long number;// declares variables for storing number
        long factorial = 1;// declare variable for storing factorial
        
    
        System.out.println("Enter a number between 1 and 25"); // tells user to enter number
        number = scanner.nextLong();
        
    
        if (number <0)  
            
         System.out.println("Positive numbers only");// if number entered is negative
        
        else if (number > 25)
            
            System.out.println("Number to large to print");
            
        
        else if (number <= 1)// if number entered is 0 or 1 
            System.out.printf("The factorial of "   number  " is equal to "   factorial);
        else {
          // if user enter 10, counter starts at 10 and runs to two
            for(long mynumber = number; mynumber >= 1; mynumber--) {
                factorial = factorial*mynumber; // mynumber would contain different values and that is multiplied by value present in factorial value and storing again in factorial variable
            }
        
        System.out.println("The factorial of "   number  " is equal to "   factorial);
        }

CodePudding user response：

To simplify the logic, you could extract it to the separate method. The logic itself is pretty strightforward:

in loop
ask a number
check if the number within the bounds
if not repeate or return if yes

public static void main(String... args) {
    Scanner scan = new Scanner(System.in);

    int num = getNumberWithin(scan, 1, 25);
}

private static int getNumberWithin(Scanner scan, int lo, int hi) {
    while (true) {
        System.out.format("Enter a number between %d and %d: ", lo, hi);
        int num = scan.nextInt();

        if (num >= lo && num <= hi)
            return num;

        System.err.format("The number should be between %d and %d\n", lo, hi);
        System.out.println();
    }
}

CodePudding user response：

boolean correctInputn= false;

while(!correctInputn)
{
long number;// declares variables for storing number
long factorial = 1;// declare variable for storing factorial


System.out.println("Enter a number between 1 and 25"); // tells user to enter number
number = scanner.nextLong();

     if (number <0)  
    {System.out.println("Positive numbers only");// if number entered is negative
    correctInputn = false; continue;} // if user enters number less than 0 loops back to code start
   
   
     else if (number > 25)
     { System.out.println("Number to large to print");
     correctInputn = false; continue;} // if user enters number over 25 loops back to code start
    

     else  {
  // if user enter 10, counter starts at 10 and runs to two
    for(long mynumber = number; mynumber >= 1; mynumber--) {
        factorial = factorial*mynumber; // mynumber would contain different values and that is multiplied by value present in factorial value and stored again in factorial variable
    }

System.out.println("The factorial of "   number  " is equal to "   factorial);
break;
}
}