Understanding the use of for loops as counting loops in homework review [closed]

Question

Newbie here, first time programmer. I have a homework assignment that I am working on. Instructions:

Write an application that allows input of an integer n between 1 and 71, and (using a for or while loop, or loops) outputs 1 asterisk on the first line of output, 2 asterisks on the second line of output, etc., through n asterisks on the nth line of output. Allow the value of n to be 1 but not 71. HINT: Use a nested loop structure.

My Code:

import java.util.Scanner;

public class Lab6a_JamesVirden
{
    public static void main(String args[])
    {
        int n;
        int sum;
        int cnt;

        sum = 0;
        cnt = 0;

        Scanner input = new Scanner(System.in);

        System.out.println();
        System.out.println();
        System.out.print("Input the total number of lines to output as anyinterger greater than 0 and less than 71:  ");
        n = input.nextInt();

        for(i = 0: i < 71; i++)
        {
            if ((n > 0) && (n < 71))
                {
                    System.out.println("*" + cnt++);

                }
                    else
                        {
                        System.out.println("The number you entered is out of range.");
                        System.out.print("Input the total number of lines to output as any interger greater than 1 and less than 71:  ");
                    n = input.nextInt();
                        }

                }

        System.out.println("Press any key to continue...");
    }
}

According to the assignment instructions, my output should display the * on line one, ** on the next line (line 2), * (line 3), etc, n = input.nextInt() is reached. Example: if n=5, output should be 5 lines beginning with one * on the first, two * on the second, etc until the output has reached 5 lines with five * on the fifth line. I am certain I am getting close, however my output which is printed isn't print multiple * on each line. Instead it is printing n*.

Any help is much appreciated. Thank you for your time.

Answer 1

yep. you are close.

Remember that print will just print the character with no carriage return but that println will print the character and then go onto a new line.

You need to do a little bit of work around this code block

if ((n > 0) && (n < 71))
{
    System.out.println("*" + cnt++);
}

Not every * needs a New Line printed after it, only that last * that belongs on that line.

There are some other small issues in there around the way you're using your for loops & if(checks) but that should at least get you in the direction of a working solution for now.

Answer 2

Even if it is not in the question :

    System.out.println();
    System.out.println();
    System.out.print("In......)

can be write:

    System.out.print("\n\nIn......)

and you can initialize local variable directly (EDIT after comment)

    int sum = 0;
    int cnt = 0;

and suppress

    sum = 0;
    cnt = 0;

so you can remove last lines

Read Effective Java to know how write good code