How do I display the asterisks according to the number entered?

Question

I am currently studying Java all by myself and I really want to learn a lot. I asked my programmer friend to give me some tasks and he gave me this.

How do I display the asterisks according to the number I input?

EXAMPLE

Enter Number:7
*
**
***
*

I have written a code but I still can't get it. Please some examples, please?

import java.util.Scanner;

public class Diamond {

    public static void main(String[] args) {

         Scanner input = new Scanner( System.in );

         /*promt for input*/
         System.out.println( "Enter number: " );
         int how_many = input.nextInt();

         for(int i = 1; i <= how_many; i++ ) {
            for(int j = 1; j <= i; j++ ) {
                System.out.print( "*" );
            }
            System.out.println("");
         }

         input.close();
    }
}

Any help or suggestion would be much appreciated.

Answer 1

Your code is fine. You are just missing the variable declarations. Probably you come from a JavaScript background. Declare int before each one of the variables (how_many, i, and j) and try to compile & execute it again.

System.out.println( "Enter number: " );

int how_many = input.nextInt();

for(int i = 1; i <= how_many; i++ ) {
    for(int j = 1; j <= i; j++ ) {
        System.out.print( "*" );
    }
    System.out.println("");
}

Also. I am assuming you have the Scanner object declared before everything

import java.util.*;
// etc, etc

Scanner input = new Scanner(System.in);

I think I understood what you were asking:

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

    System.out.println( "Enter number: " );

    int how_many = input.nextInt();

    outer:
    for(int i = 1, count = 0; i <= how_many; i++ ) {
        for(int j = 1; j <= i; j++ ) {
            if(count >= how_many)
                break outer;
            System.out.print( "*" );
        }
        System.out.println("");
    }

    input.close();
}

Answer 2

class Print{

    public static void main(String argas []){


        Scanner in=new Scanner(System.in);
        System.out.println( "Enter number: " );

        int  how_many = in.nextInt();
        int count=0;

        for(int i = 1; i <= how_many; i++ )
        {
            for(int j = 1; j <= i; j++ ) 
            {   **if(count==how_many)
                return;**
                System.out.print( "*" );
                count++;
            }
            System.out.println("");
        }

    }       
}

Add the condition to check whether the number of * are less than the input.

Answer 3

import java.util.Scanner; //program uses class Scanner

public class Print{

public static void main(String[] args){
  //declare variables
  int num; 
  int x; //outer counter
  int y; //inner counter

  //use Scanner to obtain input
  Scanner input = new Scanner(System.in);
  System.out.print("Enter number: ");
  num = input.nextInt();

   //use for loop to generate the size of bar chart
   for(x = 0; x < num; x++)
   {
       for(y = 0; y < num; y++)
       {
          System.out.print("* ");
        } 

        System.out.println();
    }     
}

}