I want to make a java pattern like this using while loops
* * * *
* * *
* *
*
and here is my code
int i = 4;
int j = 0;
while (i >= 0) {
while (j < i) {
System.out.print(" * ");
j++;
}
System.out.print("\n");
i--;
}
but its giving output like this:
* * * *
Does anyone knows what to do....?
TRY CONSIDERING THIS ONE MIGHT HELP YOU !!
Using FOR Loop
public class DownwardTrianglePattern {
public static void main(String[] args) {
int rows = 4;
//outer loop
for (int i = rows-1; i >= 0 ; i--) {
//inner loop
for (int j = 0; j <= i; j++) {
//prints star and space
System.out.print("*" + " ");
}
//throws the cursor in the next line after printing each line
System.out.println();
}
}
}
Using While Loop
public class Itriangle {
public static void main(String[] args) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter N : ");
int n = sc.nextInt();
System.out.print("Enter Symbol : ");
char c = sc.next().charAt(0);
int i = n, j;
while(i > 0) {
j = 0;
while(j++ < i) {
System.out.print(c);
}
System.out.println();
i--;
}
}
}
After i--;
you can j=0;
The problem in your code is that in first iteration after completing both the while loops the value of variables is i=3 and j=4. So for the next iteration the first while loop will run as the condition is true i.e. 3>=0 but for the next while loop the condition will be false as j i.e. 3 not less than i i.e. 3. So that's why the next loop does not executes and you are getting that output.
The j needs to be initialized inside loop.
I changed the code as below. it's giving correct output
int i = 4;
while (i >= 0) {
int j = 0;
while (j < i) {
System.out.print(" * ");
j++;
}
System.out.print("\n");
i--;
}
please reset j after j loop
int i = 4;
int j = 0;
while (i >= 0) {
while (j < i) {
System.out.print(" * ");
j++;
}
j = 0;
System.out.print("\n");
i--;
}
when you're finished with inner loop you have to reset j value else it's value will remain 4 which is not less then i value. you can reset the value before starting inner while
int i = 4;
int j = 0;
while (i >= 0) {
j = 0;
while (j < i) {
System.out.print(" * ");
j++;
}
System.out.println(""); // println will work same as System.out.print("\n") in this scenario
i--;
}
By the way your problem can be nicely solved using recursion
public static void main(String[] args) {
printLine(4);
}
private static void printLine(int numberOfStars) {
if(numberOfStars == 0) {
return;
}
System.out.println("* ".repeat(numberOfStars));
printLine(numberOfStars - 1);
}
Output
* * * *
* * *
* *
*
Related
I want to print the pattern in java and I have tried the following code. please guide me to solve my mistake.
import java.util.*;
class sp10
{
public static void main(String args[])
{
int i,j,n;
Scanner sc = new Scanner(System.in);
System.out.println("Enter value of n");
n = sc.nextInt();
for(i=n;i>=1;i--)
{
for(j=i;j<n;j++)
{
System.out.print(" ");
}
for(j=1;j<=(2*i-1);j++)
{
if(j==1 || j==(2*i-1) ||i==n)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
for(i=2;i<=n;i++)
{
for(j=i;j<n;j++)
{
System.out.print(" ");
}
for(j=1;j<=(2*i-1);j++)
{
if(j==1 || j==(2*i-1)|| i==n)
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
}
}
I am trying it in Java. Can you please guide me? It should print 5 stars in the first and the last line. Given below is the exact pattern
*****
* *
* *
*
* *
* *
*****
Well, let's look at the pattern.
n = 5
*****
* *
* *
*
* *
* *
*****
The first line and the last line is just print * n times.
private static void printTop(int n) {
System.out.println("*".repeat(n));
}
private static void printBottom(int n) {
printTop(n);
}
Though I wrote two methods here, you can just define one method like printStar(int n) and reuse it on the first and last line.
The real problem is to implement the middle part. Well, this still can be implemented in a relatively simple way. You just need to move * from column 0 to right and from n-1 to left as the row increased.
private static void printMiddle(int n) {
for (int i = 0; i < n; i++) {
int p = i;
for (int j = 0; j < n; j++) {
if (j == p || j == n - 1 - p) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
p is the offset from column 0 to right or column n-1 to left.
Now, you have everything. You can write the main method like the following:
public static void main(String args[]) {
Scanner sc = new Scanner(System.in);
System.out.println("Enter value of n");
int n = sc.nextInt();
printTop(n);
printMiddle(n);
printBottom(n);
}
I suggest the following solution:
import java.util.*;
public class sp10 {
public static void main(String args[]) {
int i, j, n;
Scanner sc = new Scanner(System.in);
System.out.println("Enter value of n");
n = sc.nextInt();
System.out.print(" ");
for (i = 0; i < 2*n - 3; i++) {
System.out.print("*");
}
System.out.println("");
for (i = n-1; i >= 1; i--) {
for (j = i; j <n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if (j==1 || j == (2 * i - 1) || i == n ) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println("");
}
for (i = 2; i <= n-1; i++) {
for (j = i; j < n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if (j == 1 || j == (2 * i - 1) || i == n) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println("");
}
System.out.print(" ");
for (i = 0; i < 2*n - 3; i++) {
System.out.print("*");
}
}
}
I hope is what you're looking for, because you question was a little bit difficult to understand...
With such solution the output is (for n = 4):
*****
* *
* *
*
* *
* *
*****
Probably, what you intended to do is as follows:
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
int i, j, n;
Scanner sc = new Scanner(System.in);
System.out.print("Enter value of n: ");
n = sc.nextInt();
for (i = n; i >= 1; i--) {
for (j = i; j < n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if (j == 1 || j == (2 * i - 1) || (i == n && j % 2 == 1))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
for (i = 2; i <= n; i++) {
for (j = i; j < n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if (j == 1 || j == (2 * i - 1) || (i == n && j % 2 == 1))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
}
}
A sample run:
Enter value of n: 4
* * * *
* *
* *
*
* *
* *
* * * *
However, if you insist that you need to print exactly what you have shown in the question, you can do it as follows:
import java.util.Scanner;
public class Main {
public static void main(String args[]) {
int i, j, n;
Scanner sc = new Scanner(System.in);
System.out.print("Enter value of n: ");
n = sc.nextInt();
for (i = n; i >= 1; i--) {
for (j = i; j < n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if ((j == 1 && i != n) || (j == (2 * i - 1) && i != n) || (j != 1 && i == n && j != (2 * i - 1)))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
for (i = 2; i <= n; i++) {
for (j = i; j < n; j++) {
System.out.print(" ");
}
for (j = 1; j <= (2 * i - 1); j++) {
if ((j == 1 && i != n) || (j == (2 * i - 1) && i != n) || (j != 1 && i == n && j != (2 * i - 1)))
System.out.print("*");
else
System.out.print(" ");
}
System.out.println("");
}
}
}
Output:
Enter value of n: 4
*****
* *
* *
*
* *
* *
*****
I am trying to write a program that outputs a Z pattern that is n number of * across the top, bottom, and connecting line using for loops.
Example:
Enter a number: 6
******
*
*
*
*
******
This is my current code, it's producing a half pyramid upside down.
import java.util.*;
public class ZShape {
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter a number: ");
int n = input.nextInt();
for (int x = 0; x <= n; x++) {
for (int y = n; y >= 1; y--) {
if (y > x) {
System.out.print("* ");
}
else
System.out.print(" ");
}
System.out.println();
}
}
}
This is the logic in the following code:
Loop over each row of the output (so from 0 to n excluded so that we have n rows)
Loop over each column of the output (so from 0 to n excluded so that we have n columns)
We need to print a * only when it is the first row (x == 0) or the last row (x == n - 1) or the column is in the opposite diagonal (column == n - 1 - row)
Code:
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
System.out.print("Enter a number: ");
int n = input.nextInt();
for (int row = 0; row < n; row++) {
for (int column = 0; column < n; column++) {
if (row == 0 || row == n - 1 || column == n - 1 - row) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
}
Sample output for n = 6:
******
*
*
*
*
******
(Note that this output has trailing white-spaces for each row, you did not specify whether they should be included, but it is easy to remove them by adding another check).
How about using three loops instead?
for (int x = 0; x < n; x++) {
System.out.print("*");
}
System.out.println();
for (int x = n-3; x >= 0; x--) {
for (int y = x; y >= 0; y--) {
System.out.print(" ");
}
System.out.println("*");
}
for (int x = 0; x < n; x++) {
System.out.print("*");
}
public class Star {
public static void main(String[] args) {
for (int i = 0; i <=4; i++) {
for (int j = 0; j <=4; j++)
{
if (i==4 || (i+j)==4 || i==0)
{
System.out.print(" * ");
}
else
{
System.out.print(" ");
}
}
System.out.println(" ");
}
}
}
Here is a logic to print Z shape:
when i = 1, then the First line will print only "#"
when i = n, then the Last line will print in same way by "#" only
when i = j, that means it will execute one diagonal line by "#" only
Code:
public static void main(String[] args) {
Scanner scr = new Scanner(System.in);
int n = scr.nextInt();
for (int i = 1; i <= n; i++) {
for(int j = n; j >= 1; j--) {
if (i == 1 || i == n || i == j) {
System.out.print("# ");
}
else {
System.out.print(" ");
}
}
System.out.println();
}
}
Good day guys! So I'm self learning java right now. And one of the exercises I'm answering now is creating a program Pyramid.java that takes an input N and prints a
pyramid whose each side is of length N, like the one below: My problem is that everytime I put an input on the command line, the 3 asterisk in the middle don't appear.
*
* *
* * *
* * * *
* * * * *
Here's my code
public class D2Q6 {
public static void main(String[] args) {
int N = Integer.parseInt(args[0]);
int k = 1;
for(int i = 1; i <= N; i++) {
for(int j = 0; j < N-i; j++)
System.out.print(" ");
System.out.print("*");
if(i > 1) {
if(i == N) {
for(int j = 0; j < i-1; j++)
System.out.print(" *");
}
else {
for(int j = 0; j < k; j++)
System.out.print(" ");
k = k+2;
System.out.print("*");
}
}
System.out.println();
}
}
I presume you are trying to execute your program through eclipse or some editor with its own console. The issue might not be with the program, but with the font (type and size) used in console.
Try running the program in DOS prompt, and you might be able to see your desired outcome.
public class PrintPyramidStar
{
public static void main(String args[])
{
int c = 1;
for (int i = 1; i <= 8; i++)
{
for (int j = i; j < 8; j++)
{
System.out.print(" ");
}
for (int k = 1; k <= c; k++)
{
if (k % 2 == 0)
System.out.print(" ");
else
System.out.print("*");
}
System.out.println();
c += 2;
}
}
}
Above is a random star program I picked using search. Running the same via eclipse console gave me skewed triangle, wherein running the same via windows command prompt gave me a perfect triangle.
I stepped through your program in Eclipse and thought the problem might be here. Currently this is printing a blank space.
else {
for(int j = 0; j < k; j++)
System.out.print(" ");
k = k+2;
System.out.print("*");
}
If you change it to the below, it prints solid asterisk then an extra one at the end;
else {
for(int j = 0; j < k; j++)
System.out.print("*");
k = k+2;
System.out.print("*");
}
However I assume that you are going for a '* * *' kind of thing, but hopefully that narrows it for you.
I would start by creating two methods, one to get the spaces and one to get the asterisks. Something like,
private static String getNSpaces(int n) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < n; i++) {
sb.append(' ');
}
return sb.toString();
}
private static String getNAsterisks(int n) {
StringBuilder sb = new StringBuilder();
for (int i = 0; i < n; i++) {
if (i != 0) {
sb.append(' ');
}
sb.append('*');
}
return sb.toString();
}
Then your main method can be as simple as -
for (int i = 1; i <= N; i++) {
System.out.print(getNSpaces(N - i));
System.out.println(getNAsterisks(i));
}
When I run the above with N equal to 5 I get
*
* *
* * *
* * * *
* * * * *
I thought I would post an alternative, brief approach to this common programming exercise.
public static void main(String args[]) {
System.out.println(pyramid(Integer.parseInt(args[0])));
}
public static String pyramid(int size) {
return line(size, size);
}
public static String line(int max, int size) {
return size < 1 ? "" : line(max, size - 1) + copies(" ", max - size) + copies("* ", size) + '\n';
}
public static String copies(String s, int size) {
return size < 1 ? "" : String.formatîui("%0" + size + "d", 0).replace("0", s);
}
See live demo
This uses recursion and breaks the code up into meaningful methods that each have their own task that is accomplished in one line.
This is not a high performance solution, but would be fast enough for moderate sizes. It is written for readability and method cohesion.
I am trying to output Pascal's triangle with asterisks (*). This is my code:
public static void main(String [] arg)
{
int n=3;
for(int i=0;i<n;i++)
{
for(int j=0;j<n-i;j++)
{
System.out.print(" ");
}
boolean b=true;
for(int k=0;k<i*2+1;k++)
{
if(b)
{
System.out.print("*");
b=false;
}
else
{
System.out.print(" ");
b=true;
}
}
}
System.out.println(" ");
}
}
I have rechecked several times and failed to find any error.
Also let me know whether the if-block is implemented correctly.
The following code is not giving the required output as below:
*
* *
* * *
Your System.out.println() statement is outside of your for loop instead of inside.
for (int i = 0; i < n; i++) {
for (int j = 0; j < n - i; j++) {
System.out.print(" ");
}
boolean b = true;
for (int k = 0; k < i * 2 + 1; k++) {
if (b) {
System.out.print("*");
b = false;
} else {
System.out.print(" ");
b = true;
}
}
}
System.out.println(" "); // called only once
// output is
// * * * * * *
Just move it inside the close brace and your program will work.
for (int i = 0; i < n; i++) {
for (int j = 0; j < n - i; j++) {
System.out.print(" ");
}
boolean b = true;
for (int k = 0; k < i * 2 + 1; k++) {
if (b) {
System.out.print("*");
b = false;
} else {
System.out.print(" ");
b = true;
}
}
System.out.println(" "); // called once for each iteration
}
// output is
// *
// * *
// * * *
make inner loop reverse
for(int j=n-i;j>0;j--)
{
System.out.print(" ");
}
this should print from 3 starts then 2 then 1 star
Hi there i want to create a triangle using java loops. But what i need is only the borders. I've tried using this syntax but it always shows error. any advice?
int lines = 5;
int c = 2*lines;
for (int i = lines-1; i>=0; i--)
{
for (int j = i; j < lines; j++)
{
System.out.print(" ");
}
for (int k = 1; k <= c; k++)
{
if (k % 2 == 0)
{
System.out.print(" ");
}
else
{
if (k == 0 || k == lines - 1) {
System.out.print("*");
}
}
}
System.out.print("\n");
c -= 2;
}
can you kindly help me . thanks
There's a lot of things wrong with your code...
for (int k = 1; k <= c; k++)
// and then:
if (k == 0 || k == lines - 1) {
k will never be 0
if (k % 2 == 0)
// and then
else
{
if (k == 0 || k == lines - 1) {
a even if k was 0, then 0%2 == 0, so k==0 can never occur
As of right now, your app only prints spaces.
If you want to draw a triangle, the (possibly) simplest way would be to do
public static void main(String[] args) {
int lines = 6;
int cols = lines+1;
for (int line =0; line < lines-1; line++) {
for (int col = 0; col<cols; col++) {
if (col == 0 || col == line) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.println();
}
for (int col=0; col<cols; col++) {
System.out.print("*");
}
System.out.println();
}
Triangle.java
public class Triangle {
private int lines;
public Triangle(int lines) {
this.lines = lines;
display();
}
public void display() {
int spaces = lines - 1;
int last;
int min = 1;
int max;
for (int i = 0; i < lines; i++) {
last = 2 * i + 1;
max = spaces + last;
for (int j = min; j <= max; j++) {
if (j == spaces + 1 || j == max || i == lines - 1)
System.out.print('*');
else
System.out.print(' ');
}
System.out.println();
spaces--;
}
}
public static void main(String[] args) {
new Triangle(3);
new Triangle(4);
new Triangle(5);
new Triangle(6);
}
}
Output
*
* *
*****
*
* *
* *
*******
*
* *
* *
* *
*********
*
* *
* *
* *
* *
***********
Ex:
*
* *
* *
* *
*********
Code:
int numberOfRows = 5;
for(int i=0; i<numberOfRows; i++)
{
for(int a=0; a<=numberOfRows; a++)
{
int x = numberOfRows - i;
if (a > x) {
if (x==(a-1) || i==(numberOfRows-1)) {
System.out.print("*");
} else {
System.out.print(" ");
}
} else {
System.out.print(" ");
}
}
for(int b=0; b<=i; b++)
{
if(b==i || i==(numberOfRows-1)) {
System.out.print("*");
} else {
System.out.print(" ");
}
}
System.out.print("\n");
}
I have used two methods and repeated those two methods using for loop.
public class OpenWord {
int i;
String k = " ";
public void space(){
System.out.println("*"+k+"*");
}
public void star(){
System.out.println("*");
}
public void trainagle(){
star();
for ( i=1; i<=10;i++){
space();
k =k+" ";
if(i==10){
k=k.replace(" ", "*");
space();
}
}
}
public static void main(String args[]) {
OpenWord a = new OpenWord();
a.trainagle();
}
}
Output:
*
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
* *
******************