Number Patterns using loops in Java

Question

I have been trying different variations of for loops and have no clue how to make these patterns:

Pattern 1

54321
5432
543
54
5

Pattern

Answer 1

Your inner for loop

for (int j = (rows + 1 - i) ; j  > 0 ; j-- ){
    System.out.print(j);
}

will always count down to 1, because it keeps going until j is zero. Also, the number that the current row starts on will depend on the current row, because you used i in your assignment to j. To get pattern 1 both of those things will have to change.

Answer 2

Since you posted an attempt for pattern one, I'll tell you a solution for pattern one -

int rows = 5; // <- Start at 5.
for (int i = rows; i > 0; i--) { // <- Use decrementing loop(s).
  for (int j = rows; j > rows - i; j--) { // <- Start at 5 (again)
    System.out.print(j);
  }
  System.out.println();
}

Output is pattern 1 in your question,

54321
5432
543
54
5

Answer 3

Try this:

public class NumberPattern {
  public static void main(String[] args) {

    for (int i = 1; i <= 3; i++) {

        for (int k = 2; k >= i; k--) {
            System.out.print(" ");
        }

        for (int j = 1; j <= (2 * i - 1); j++) {
            System.out.print(j);
        }
        System.out.println();

    }
    for (int i = 1; i <= 2; i++) {

        for (int k = i; k > 0; k--) {
            System.out.print(" ");
        }

        if (i % 2 != 0) {

            for (int j = 1; j <= (2 * i + 1); j++) {
                System.out.print(j);
            }
        } else {
            for (int j = 1; j <= (i / 2); j++) {
                System.out.print(j);
            }
        }
        System.out.println();

    }
}

}

Answer 4

import java.util.Scanner;

public class Triangle {
    public static void main(String[ ] args){

        Scanner scan = new Scanner(System.in);
        System.out.println("enter no.of line you need");
        int n = scan.nextInt();
            for(int i=1;i<=n;i++){
                for(int j=5;j>=i;j--){
                    System.out.print(j);
            }
                System.out.println(" ");
            }}}

Answer 5

public static void main(String[] args) {

        int rows = 5;
        System.out.println("------ PATTERN 1 ------");

        for (int i = 1 ; i <= rows ; i++){
            for (int j = rows; j >= i ; j--){
                System.out.print(j);
            }
            System.out.println();

        }


        System.out.println("\n------ PATTERN 2 ------");

        for (int i = 1 ; i <= rows ; i++){
            int k;
            for (k = rows ; k > i; k--){
                System.out.print(" ");
            }
            for (int j = 1; j <= k ; j++){
                System.out.print(j);
            }
            System.out.println();

        }

        System.out.println("\n------ PATTERN 3 ------");


        for (int i = rows ; i >= 1 ; i--){
            int k;
            for (k = rows ; k > i; k--){
                System.out.print(" ");
            }
            for (int j = 1; j <= k ; j++){
                System.out.print(j);
            }
            System.out.println();   
        }

        System.out.println("\n------ PATTERN 4 ------");

        int whitespaces = rows/2;
        for (int i = 1 ; i <= rows; i++){
            // absolute value of whitespaces
            int abs_whitespaces = 
                    (whitespaces < 0 ? -whitespaces : whitespaces);
            for (int j = 0 ; j < abs_whitespaces ; j++){
                System.out.print(" ");
            }

            for (int j = 1 ; j <= rows - 2 * abs_whitespaces ; j++){
                System.out.print(j);
            }

            whitespaces-=1;
            System.out.println();

        }
    }

Answer 6

The first program is:

class timepass {
    public static void main() {
        for (int a = -1;a<=5;a++) {
            for(int b = 5; b >= a;b--) {
                System.out.print("*");   
            }
            System.out.println();
            // enter code here
        }
    }
}

The second program is:

class timepass {
    public static void main() {
        for(int i = 1;i<= 6;i++) {
            for(int j = 1;j<= i ;j++) {
                System.out.print("*");
            }
            System.out.println();
        }
    }
}