JavaScript Problem

Question

5-15) (Triangle Printing Program) Write an application that displays the following patterns separately, one below the other. The use should be asked to enter an integer that will determine how many lines of the pattern are printed out. Use for loops to generate the patterns. All asterisks (*) should be printed by a single statement of the form System.out.print('*'); which causes the asterisks to print side by side. A statement of the form System.out.println(); can be used to move to the next line. A statement of the form System.out.print(' '); can be used to display a space for the last two patterns. There should be no other output statements in the program. [Hint: The last two patterns require that each line begin with an appropriate number of blank spaces.]

Intended output:

Enter◦an◦integer◦to◦be◦a◦limit◦of◦the◦pattern:Pattern◦A:⏎

*⏎

**⏎

***⏎

****⏎

⏎

Pattern◦B:⏎

****⏎

***⏎

**⏎

*⏎

⏎

Pattern◦C:⏎

****⏎

◦***⏎

◦◦**⏎

◦◦◦*⏎

⏎

Pattern◦D:⏎

◦◦◦*⏎

◦◦**⏎

◦***⏎

****⏎

Answer 1

import java.util.Scanner;

class StarPattern

{

private Scanner scanner;

private int N;

public StarPattern()

{

scanner = new Scanner(System.in);

N=-1;

}

public void Input()

{

N=-1;

while (N<1 || N>25)

{

System.out.print(" How many ??? :>");

N = scanner.nextInt();

if (N<0) { System.out.println(" Invalid "); }

if (N>25) { System.out.println(" Too many "); }

}

}

public void Forward()

{

if (N>0)

{

for (int iLoop=0; iLoop<N; iLoop++)

{

for (int jLoop=0; jLoop<=iLoop; jLoop++)

{

System.out.print("*");

}

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

}

}

}

public void Backward()

{

if (N>0)

{

for (int iLoop=N-1; iLoop>=0; iLoop--)

{

for (int jLoop=0; jLoop<=iLoop; jLoop++)

{

System.out.print("*");

}

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

}

}

}

public void forward()

{

for (int iLoop=N; iLoop>=1; iLoop--)

{

for (int j=1; j<iLoop; j++)

{

System.out.print(" ");

}

for (int j=iLoop; j<=N; j++)

{

System.out.print("*");

}

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

}

}

public void backward()

{

int iLoop,jLoop;

for (iLoop=N; iLoop>=1; iLoop--)

{

for (jLoop=0; jLoop<N-iLoop; jLoop++)

{

System.out.print(" ");

}

for (; jLoop<N; jLoop++)

{

System.out.print("*");

}

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

}

}

public static void main(String args[])

{

StarPattern starPattern = new StarPattern();

starPattern.Input();

starPattern.Forward(); System.out.println("");

starPattern.Backward();System.out.println("");

starPattern.backward();System.out.println("");

starPattern.forward();

}

}