am trying to do this triangle using 2 arguments.
Can someone help me out and see what is wrong with my code?
I can't seems to flip it to the same as this image.
Thank you!
int width = Integer.parseInt(args[0]);
int height = Integer.parseInt(args[1]);
for (int i = 0; i < height; i++) {
int starsThisLine = (int) Math.round(width * ((i + 1) / (double) height));
int dotsBeforeStars = Math.round((width - starsThisLine));
for (int j = 0; j < width; j++) {
if (j > dotsBeforeStars) {
System.out.print(".");
} else if (j < (dotsBeforeStars + starsThisLine)) {
System.out.print("*");
} else {
System.out.println(1);
Here is one way to do it. Just create a repeat method to return the String with the proper number of characters.
int height = 10;
for (int i = 0; i < height; i++) {
System.out.println(repeat("*", height-i)+repeat(".",i));
}
public static String repeat(String a, int count) {
StringBuilder sb = new StringBuilder();
while(count-- > 0) {
sb.append(a);
}
return sb.toString();
}
Both will print
**********
*********.
********..
*******...
******....
*****.....
****......
***.......
**........
*.........
One observation. Notice the first line has all stars. But that last line does not have all dots. The same was true in your patterns too.
If you want the start and finish to look like this:
**********
..........
The loop should be as follows:
for (int i = 0; i <= height; i++) {
If you want the start and finish to look like this:
*********.
*.........
The loop should be as follows:
for (int i = 1; i < height; i++) {
Assuming that the height and width will always be the same, here is an example implementation that uses a scanner (you can change this if you want to):
import java.util.Scanner;
class Main {
public static void main(String[] args) {
Scanner scan = new Scanner(System.in);
int dimensions = scan.nextInt();
for(int i = 0; i < dimensions; i++){
for(int dots = 0; dots < i; dots++){
System.out.print(". ");
}
for(int stars = dimensions; stars > i; stars--){
System.out.print("* ");
}
System.out.println();
}
}
}
In this example, our outer for loop with the dimensions represents the code for each row of the triangle, in this case, if we inputted 5, 5 rows.
Then, we start with printing dots since they are on the left side. Since the number of dots goes 0 -> 1 -> 2 -> 3 -> 4, this is equivalent to what "i", or our outer loop counter is.
With the stars, the number of stars goes 5 -> 4 -> 3 -> 2 -> 1, so if we just count backwards from the number of rows to our counter variable, we can get this number.
I'm taking a beginners Java course over the summer. I need to make a pyramid using loops for homework. The pyramid has to be made out of asterisks; in addition, size of pyramid is determined by user.
This is what I have for code now;
public class Pyramid {
public static void main(String[] args) {
int size = 6;
for (int x = 0; x < size; x++) {
for (int y = x; y < size; y++) {
}
for (int z = 0; z <= x; z++) {
System.out.print("*");
}
System.out.println("");
}
}
}
The problem of my code is that the number of asterisks in each row is wrong by one.
for (int z = 0; z <= x; z++) {
will execute the loop until z <= x is no longer true. That means it executes for z=0, z=1, z=2, ..., z=x--which means it actually executes the loop x+1 times. (The next z, z=x+1, is the first z that makes z<=x false.)
The normal idiom in Java (and other language with C-like for statements) is to start at 0 and use < when checking for the upper bound:
for (int z = 0; z < x; z++) {
You'll run into cases where you want to use <=, and you'll run into cases where you want to start at 1 instead of 0, but the majority of for loops with an integer index follow this form.
If I understand your question correctly :
public class Pyramid {
public static void main(String[] args) {
int size =6;
for (int i = 1; i <= size; i++) {
for (int x = size - 1; x >= i; x--) {
System.out.print(" ");
}
for (int y = 1; y<= i; y++) {
System.out.print("*");
}
for (int z= 1; z <= i - 1; z++) {
System.out.print("*");
}
System.out.println();
}
}
}
The output is :
*
***
*****
*******
*********
***********
If I understand your question, you could do something like this
int levels = 0;
Scanner input = new Scanner(System.in);
while (levels < 1) {
System.out.println("What size triangle would you like?");
if (input.hasNextInt()) {
levels = input.nextInt();
} else if (input.hasNext()) {
System.out.println("Not a valid size: " + input.next());
} else {
System.err.println("no more input");
System.exit(1);
}
}
for (int i = 1; i <= levels; i++) {
StringBuilder sb = new StringBuilder();
int t = i;
while (--t > 0) {
sb.append("*");
}
StringBuilder spaces = new StringBuilder();
for (t = 0; t < levels - i; t++) {
spaces.append(' ');
}
System.out.println(spaces.toString() + sb + "*" + sb);
}
To solve this problem it's best to think about the numbers that go into it...
*
***
*****
If you label the parts of the triangle
* row 1, 2 spaces, 1 star
*** row 2, 1 space, 3 stars
***** row 3, 0 spaces, 5 starts
Then you can just start playing with the numbers
The number of spaces to display is 3 - row # + 1
The number of stars to display is 2 * row - 1
Then construct a loop to draw each line.
within this loop, you need a loop to draw the number of spaces
and a loop to draw the number of stars
This is a homework question so I would like help, not an answer.
I'm trying to create 2 triangles out of numbers based on a number entered by the user.
"Enter a number between 2-9: "3"
1
12
123
1
21
321
IE2:
"Enter a number between 2-9: "5"
1
12
123
1234
12345
1
21
321
4321
54321
I have been able to get the first triangle complete. But when I add my nested loop it messes up my first triangle with the numbers developed from the nested loop. It also puts all the numbers in a straight vertical line. I've tried variations for different nest loops and even tried messing with a StringBuilder, but was still unsuccessful.
Here's what I have in code so far:
import java.util.Scanner;
public class NestedLoops
{
public static void main(String[] args)
{
Scanner input = new Scanner(System.in);
System.out.print("Enter a Number between 2-9: ");
int width = input.nextInt();
String r = "";
for (int i = 1; i <= width; i++)
{
r = r + i;
System.out.println(r);
}
}
}
Again, I'm looking for help/understanding and not just an answer.
There are two aspects the 2nd part of the question.
You need to generate strings with the numbers in the reverse order:
You could do this by adding the numbers at the other end.
You could do this by reversing the strings.
You need to arrange that there are spaces to the left.
You could do this by adding the required number of spaces to the left end of the string.
You could do this by using the System.out.format(...) with a template that right aligns the string in a field with the required number of characters. (OK, that's a bit too obscure ...)
Or, you can build the string in a character array or string builder rather than using string concatenation.
The "trick" is to figure out what strategy you are going to use ... before you start cutting code.
try
int width = 5;
// for all lines; number of lines = width
for (int line = 1; line <= width; line++) {
// print numbers from 1 to current line number
for (int n = 1; n <= line; n++) {
System.out.print(n);
}
// end of line
System.out.println();
}
// add empty line between triangles
System.out.println();
// for all lines; number of lines = width
for (int line = 1; line <= width; line++) {
// printing padding spaces, number of spaces = with - line number
int nSpaces = width - line;
for (int i = 0; i < nSpaces; i++) {
System.out.print(" ");
}
// print numbers from number of current line to 1
for (int n = line; n >= 1; n--) {
System.out.print(n);
}
// end of line
System.out.println();
}
Can you just add another loop after your first loop like
String r = "";
String space = "";
for (int i = width; i >= 1; i--)
{
r = r + i;
System.out.println(r);
}
Try it. not yet tested
You need to use a queue.
eg. http://docs.oracle.com/javase/1.5.0/docs/api/java/util/LinkedList.html
Enque the numbers till you reach the max, and then start dequing them.
And while you dequeue, you need to apply the reverse
Queue<String> q = new LinkedList<String>();
for (int i = 1; i <= width; i++)
{
r = r + i;
q.add(r);
System.out.println(r);
}
while(!q.isEmpty()){
String j = q.remove();
//reverse j
System.out.println(reverse(j));
}
I leave the reversing part for you to do :)
public static void main(String[] args)
{
int n = 5;
for(int i=1; i<=n; i++)
{
for (int j=(n*2), k=n; j>1; j--)
{
if (k <= i)
{
System.out.print(k);
}
else
{
System.out.print('*');
}
k += (j)-1 > n ? -1 : 1;
}
System.out.println();
}
}
Just tried to implement in scala. Ignore if you don't like it..:-)
class Triangle extends App
{
val width = Console.readInt()
if (width < 2 || width > 9)
{
throw new RuntimeException()
}
var i, j = 1;
for (i <- 1 to width)
{
for (j <- 1 to i)
{
print(j)
}
print("\n")
}
for (i <- 1 to width)
{
for (dummy <- 1 to width-i)
{
print(" ")
}
for (j <- i to 1 by -1)
{
print(j)
}
print("\n")
}
}
My assignment in my Java course is to make 3 triangles. One left aligned, one right aligned, and one centered. I have to make a menu for what type of triangle and then input how many rows is wanted. The triangles have to look like this
*
**
***
****
*
**
***
****
*
***
*****
So far I was able to do the left aligned triangle but I can't seem to get the other two. I tried googling but nothing turned up. Can anyone help? I have this so far.
import java.util.*;
public class Prog673A
{
public static void leftTriangle()
{
Scanner input = new Scanner (System.in);
System.out.print("How many rows: ");
int rows = input.nextInt();
for (int x = 1; x <= rows; x++)
{
for (int i = 1; i <= x; i++)
{
System.out.print("*");
}
System.out.println("");
}
}
public static void rightTriangle()
{
Scanner input = new Scanner (System.in);
System.out.print("How many rows: ");
int rows = input.nextInt();
for (int x = 1; x <= rows; x++)
{
for (int i = 1; i >= x; i--)
{
System.out.print(" ");
}
System.out.println("*");
}
}
public static void centerTriangle()
{
}
public static void main (String args [])
{
Scanner input = new Scanner (System.in);
System.out.println("Types of Triangles");
System.out.println("\t1. Left");
System.out.println("\t2. Right");
System.out.println("\t3. Center");
System.out.print("Enter a number: ");
int menu = input.nextInt();
if (menu == 1)
leftTriangle();
if (menu == 2)
rightTriangle();
if (menu == 3)
centerTriangle();
}
}
Sample Output:
Types of Triangles
1. Left
2. Right
3. Center
Enter a number (1-3): 3
How many rows?: 6
*
***
*****
*******
*********
***********
Hint: For each row, you need to first print some spaces and then print some stars.
The number of spaces should decrease by one per row, while the number of stars should increase.
For the centered output, increase the number of stars by two for each row.
Ilmari Karonen has good advice, and I'd just like to generalize it a bit. In general, before you ask "how can I get a computer to do this?" ask "how would I do this?"
So, if someone gave you an empty Word document and asked you to create the triangles, how would you go about doing it? Whatever solution you come up with, it's usually not hard to translate it to Java (or any other programming language). It might not be the best solution, but (hopefully!) it'll work, and it may point you to a better solution.
So for instance, maybe you would say that you'd type out the base, then go up a line, then type the next highest line, etc. That suggests that you can do the same in Java -- create a list of Strings, base-to-top, and then reverse them. That might suggest that you can just create them in reverse order, and then not have to reverse them. And then that might suggest that you don't need the list anymore, since you'll just be creating and printing them out in the same order -- at which point you've come up with essentially Ilmari Karonen's advice.
Or, maybe you'd come up with another way of doing it -- maybe you'd come up with Ilmari Karonen's idea more directly. Regardless, it should help you solve this and many other problems.
Left alinged triangle-
*
**
from above pattern we come to know that-
1)we need to print pattern containing n rows (for above pattern n is 4).
2)each row contains star and no of stars i each row is incremented by 1.
So for Left alinged triangle we need to use 2 for loop.
1st "for loop" for printing n row.
2nd "for loop for printing stars in each rows.
Code for Left alinged triangle-
public static void leftTriangle()
{
/// here no of rows is 4
for (int a=1;a<=4;a++)// for loop for row
{
for (int b=1;b<=a;b++)for loop for column
{
System.out.print("*");
}
System.out.println();}
}
Right alinged triangle-
*
**
from above pattern we come to know that-
1)we need to print pattern containing n rows (for above pattern n is 4).
2)In each row we need to print spaces followed by a star & no of spaces in each row is decremented by 1.
So for Right alinged triangle we need to use 3 for loop.
1st "for loop" for printing n row.
2nd "for loop for printing spaces.
3rd "for loop" for printing stars.
Code for Right alinged triangle -
public void rightTriangle()
{
// here 1st print space and then print star
for (int a=1;a<=4;a++)// for loop for row
{
for (int c =3;c>=a;c--)// for loop fr space
{
System.out.print(" ");
}
for (int d=1;d<=a;d++)// for loop for column
{
System.out.print("*");
}
System.out.println();
}
}
Center Triangle-
*
* *
from above pattern we come to know that-
1)we need to print pattern containing n rows (for above pattern n is 4).
2)Intially in each row we need to print spaces followed by a star & then again a space . NO of spaces in each row at start is decremented by 1.
So for Right alinged triangle we need to use 3 for loop.
1st "for loop" for printing n row.
2nd "for loop for printing spaces.
3rd "for loop" for printing stars.
Code for center Triangle-
public void centerTriangle()
{
for (int a=1;a<=4;a++)// for lop for row
{
for (int c =4;c>=a;c--)// for loop for space
{
System.out.print(" ");
}
for (int b=1;b<=a;b++)// for loop for column
{
System.out.print("*"+" ");
}
System.out.println();}
}
CODE FOR PRINTING ALL 3 PATTERNS -
public class space4
{
public static void leftTriangle()
{
/// here no of rows is 4
for (int a=1;a<=4;a++)// for loop for row
{
for (int b=1;b<=a;b++)for loop for column
{
System.out.print("*");
}
System.out.println();}
}
public static void rightTriangle()
{
// here 1st print space and then print star
for (int a=1;a<=4;a++)// for loop for row
{
for (int c =3;c>=a;c--)// for loop for space
{
System.out.print(" ");
}
for (int d=1;d<=a;d++)// for loop for column
{
System.out.print("*");
}
System.out.println();
}
}
public static void centerTriangle()
{
for (int a=1;a<=4;a++)// for lop for row
{
for (int c =4;c>=a;c--)// for loop for space
{
System.out.print(" ");
}
for (int b=1;b<=a;b++)// for loop for column
{
System.out.print("*"+" ");
}
System.out.println();}
}
public static void main (String args [])
{
space4 s=new space4();
s.leftTriangle();
s.rightTriangle();
s.centerTriangle();
}
}
package apple;
public class Triangle {
private static final int row = 3;
public static void main(String... strings) {
printLeftTriangle();
System.out.println();
printRightTriangle();
System.out.println();
printTriangle();
}
// Pattern will be
// *
// **
// ***
public static void printLeftTriangle() {
for (int y = 1; y <= row; y++) {
for (int x = 1; x <= y; x++)
System.out.print("*");
System.out.println();
}
}
// Pattern will be
// *
// **
// ***
public static void printRightTriangle() {
for (int y = 1; y <= row; y++) {
for (int space = row; space > y; space--)
System.out.print(" ");
for (int x = 1; x <= y; x++)
System.out.print("*");
System.out.println();
}
}
// Pattern will be
// *
// ***
// *****
public static void printTriangle() {
for (int y = 1, star = 1; y <= row; y++, star += 2) {
for (int space = row; space > y; space--)
System.out.print(" ");
for (int x = 1; x <= star; x++)
System.out.print("*");
System.out.println();
}
}
}
This is for normal triangle:
for (int i = 0; i < 5; i++) {
for (int j = 5; j > i; j--) {
System.out.print(" ");
}
for (int k = 1; k <= i + 1; k++) {
System.out.print(" *");
}
System.out.print("\n");
}
Output:
*
* *
* * *
* * * *
* * * * *
This is for left triangle, just removed space before printing *:
for (int i = 0; i < 5; i++) {
for (int j = 5; j > i; j--) {
System.out.print(" ");
}
for (int k = 1; k <= i + 1; k++) {
System.out.print("*");
}
System.out.print("\n");
}
Output:
*
**
***
****
*****
1) Normal triangle
package test1;
class Test1 {
public static void main(String args[])
{
int n=5;
for(int i=0;i<n;i++)
{
for(int j=0;j<=n-i;j++)
{
System.out.print(" ");
}
for(int k=0;k<=2*i;k++)
{
System.out.print("*");
}
System.out.println("\n");
}
}
2) right angle triangle
package test1;
class Test1 {
public static void main(String args[])
{
int n=5;
for(int i=0;i<n;i++)
{
for(int j=0;j<=n-i;j++)
{
System.out.print(" ");
}
for(int k=0;k<=i;k++)
{
System.out.print("*");
}
System.out.println("\n");
}
}
}
}
3) Left angle triangle
package test1;
class Test1 {
public static void main(String args[])
{
int n=5;
for(int i=0;i<n;i++)
{
for(int j=0;j<=i;j++)
{
System.out.print("*");
}
System.out.println("\n");
}
}
}
I know this is pretty late but I want to share my solution.
public static void main(String[] args) {
String whatToPrint = "aword";
int strLen = whatToPrint.length(); //var used for auto adjusting the padding
int floors = 8;
for (int f = 1, h = strLen * floors; f < floors * 2; f += 2, h -= strLen) {
for (int k = 1; k < h; k++) {
System.out.print(" ");//padding
}
for (int g = 0; g < f; g++) {
System.out.print(whatToPrint);
}
System.out.println();
}
}
The spaces on the left of the triangle will automatically adjust itself depending on what character or what word you want to print.
if whatToPrint = "x" and floors = 3 it will print
x
xxx
xxxxx
If there's no automatic adjustment of the spaces, it will look like this (whatToPrint = "xxx" same floor count)
xxx
xxxxxxxxx
xxxxxxxxxxxxxxx
So I made add a simple code so that it will not happen.
For left half triangle, just change strLen * floors to strLen * (floors * 2) and the f +=2 to f++.
For right half triangle, just remove this loop for (int k = 1; k < h; k++) or change h to 0, if you choose to remove it, don't delete the System.out.print(" ");.
For the right triangle, for each row :
First: You need to print spaces from 0 to rowNumber - 1 - i.
Second: You need to print \* from rowNumber - 1 - i to rowNumber.
Note: i is the row index from 0 to rowNumber and rowNumber is number of rows.
For the centre triangle: it looks like "right triangle" plus adding \* according to the row index (for ex : in first row you will add nothing because the index is 0 , in the second row you will add one ' * ', and so on).
well for the triangle , you need to have three loops in place of two ,
one outer loop to iterate the no of line
two parallel loops inside the main loop
first loop prints decreasing no of loops
second loop prints increasing no of ''
well i could give the exact logic as well , but its better if you try first
just concentrate how many spaces and how many '' u need in every line
relate the no of symbols with loop iterating no of lines
and you're done
..... if it bothers more , let me know , i'll explain with logic and code as well
This will print stars in triangle:
`
public class printstar{
public static void main (String args[]){
int m = 0;
for(int i=1;i<=4;i++){
for(int j=1;j<=4-i;j++){
System.out.print("");}
for (int n=0;n<=i+m;n++){
if (n%2==0){
System.out.print("*");}
else {System.out.print(" ");}
}
m = m+1;
System.out.println("");
}
}
}'
Reading and understanding this should help you with designing the logic next time..
import java.util.Scanner;
public class A {
public void triagle_center(int max){//max means maximum star having
int n=max/2;
for(int m=0;m<((2*n)-1);m++){//for upper star
System.out.print(" ");
}
System.out.println("*");
for(int j=1;j<=n;j++){
for(int i=1;i<=n-j; i++){
System.out.print(" ");
}
for(int k=1;k<=2*j;k++){
System.out.print("* ");
}
System.out.println();
}
}
public void triagle_right(int max){
for(int j=1;j<=max;j++){
for(int i=1;i<=j; i++){
System.out.print("* ");
}
System.out.println();
}
}
public void triagle_left(int max){
for(int j=1;j<=max;j++){
for(int i=1;i<=max-j; i++){
System.out.print(" ");
}
for(int k=1;k<=j; k++){
System.out.print("* ");
}
System.out.println();
}
}
public static void main(String args[]){
A a=new A();
Scanner input = new Scanner (System.in);
System.out.println("Types of Triangles");
System.out.println("\t1. Left");
System.out.println("\t2. Right");
System.out.println("\t3. Center");
System.out.print("Enter a number: ");
int menu = input.nextInt();
Scanner input1 = new Scanner (System.in);
System.out.print("maximum Stars in last row: ");
int row = input1.nextInt();
if (menu == 1)
a.triagle_left(row);
if (menu == 2)
a.triagle_right(row);
if (menu == 3)
a.triagle_center(row);
}
}
public static void main(String[] args) {
System.out.print("Enter the number: ");
Scanner userInput = new Scanner(System.in);
int myNum = userInput.nextInt();
userInput.close();
System.out.println("Centered Triange");
for (int i = 1; i <= myNum; i+=1) {//This tells how many lines to print (height)
for (int k = 0; k < (myNum-i); k+=1) {//Prints spaces before the '*'
System.out.print(" ");
}
for (int j = 0; j < i; j++) { //Prints a " " followed by '*'.
System.out.print(" *");
}
System.out.println(""); //Next Line
}
System.out.println("Left Triange");
for (int i = 1; i <= myNum; i+=1) {//This tells how many lines to print (height)
for (int j = 0; j < i; j++) { //Prints the '*' first in each line then spaces.
System.out.print("* ");
}
System.out.println(""); //Next Line
}
System.out.println("Right Triange");
for (int i = 1; i <= myNum; i+=1) {//This tells how many lines to print (height)
for (int k = 0; k < (myNum-i); k+=1) {//Prints spaces before the '*'
System.out.print(" ");
}
for (int j = 0; j < i; j+=1) { //Prints the " " first in each line then a "*".
System.out.print(" *");
}
System.out.println(""); //Next Line
}
}
This is the least complex program, which takes only 1 for loop to print the triangle. This works only for the center triangle, but small tweaking would make it work for other's as well -
import java.io.DataInputStream;
public class Triangle {
public static void main(String a[]) throws Exception{
DataInputStream in = new DataInputStream(System.in);
int n = Integer.parseInt(in.readLine());
String b = new String(new char[n]).replaceAll("\0", " ");
String s = "*";
for(int i=1; i<=n; i++){
System.out.print(b);
System.out.println(s);
s += "**";
b = b.substring(0, n-i);
System.out.println();
}
}
}
For left aligned right angle triangle you could try out this simple code in java:
import java.io.*;
import java.util.*;
public class Solution {
public static void main(String[] args) {
Scanner sc=new Scanner(System.in);
int size=sc.nextInt();
for(int i=0;i<size;i++){
for(int k=1;k<size-i;k++){
System.out.print(" ");
}
for(int j=size;j>=size-i;j--){
System.out.print("#");
}
System.out.println();
}
}
}
Find the following , it will help you to print the complete triangle.
package com.raju.arrays;
public class CompleteTriange {
public static void main(String[] args) {
int nuberOfRows = 10;
for(int row = 0; row<nuberOfRows;row++){
for(int leftspace =0;leftspace<(nuberOfRows-row);leftspace++){
System.out.print(" ");
}
for(int star = 0;star<2*row+1;star++){
System.out.print("*");
}
for(int rightSpace =0;rightSpace<(nuberOfRows-row);rightSpace++){
System.out.print(" ");
}
System.out.println("");
}
}
}
*
***
*****
*******
*********
***********
*************
For center triangle
Scanner sc = new Scanner(System.in);
int n=sc.nextInt();
int b=(n-1)*2;
for(int i=1;i<=n;i++){
int t= i;
for(int k=1;k<=b;k++){
System.out.print(" ");
}
if(i!=1){
t=i*2-1;
}
for(int j=1;j<=t;j++){
System.out.print("*");
if(j!=t){
System.out.print(" ");
}
}
System.out.println();
b=b-2;
}
output:
*
* * *
for(int i=1;i<=5;i++)
{
for(int j=5;j>=i;j--)
{
System.out.print(" ");
}
for(int j=1;j<=i;j++)
{
System.out.print("*");
}
for(int j=1;j<=i-1;j++)
{
System.out.print("*");
}
System.out.println("");
}
*
***
public class Triangle {
public static void main ( String arg[] ) {
System.out.print("Enter Triangle Size : ");
int num = 0;
try {
num = Integer.parseInt( read.readLine() );
} catch(Exception Number) {
System.out.println("Invalid Number!");
}
for(int i=1; i<=num; i++) {
for(int j=1; j<num-(i-1); j++) {
System.out.print(" ");
}
for(int k=1; k<=i; k++) {
System.out.print("*");
for(int k1=1; k1<k; k1+=k) {
System.out.print("*");
}
}
System.out.println();
}
}
}
Target output:
*
***
*****
Implementation:
for (int i = 5; i >= 3; i--)
for (int a = 1; a <= i; a++)
{
System.out.print(" ");
}
for (int j = 10; j/2>=i; j--)
{
System.out.print("*");
}
System.out.println("");
}
(a) (b) (c) (d)
* ********** ********** *
** ********* ********* **
*** ******** ******** ***
**** ******* ******* ****
***** ****** ****** *****
****** ***** ***** ******
******* **** **** *******
******** *** *** ********
********* ** ** *********
********** * * **********
int line;
int star;
System.out.println("Triangle a");
for( line = 1; line <= 10; line++ )
{
for( star = 1; star <= line; star++ )
{
System.out.print( "*" );
}
System.out.println();
}
System.out.println("Triangle b");
for( line = 1; line <= 10; line++ )
{
for( star = 1; star <= 10; star++ )
{
if(line<star)
System.out.print( "*" );
else
System.out.print(" ");
}
System.out.println();
}
System.out.println("Triangle c");
for( line = 1; line <= 10; line++ )
{
for( star = 1; star <= 10; star++ )
{
if(line<=star)
System.out.print( "*" );
//else
// System.out.print(" ");
}
System.out.println();
}
System.out.println("Triangle d");
for( line = 1; line <= 10; line++ )
{
for( star = 1; star <= 10; star++ )
{
if(line>10-star)
System.out.print( "*" );
else
System.out.print(" ");
}
System.out.println();
}
You might be interested in this too
Scanner sc = new Scanner(System.in);
int n=sc.nextInt();
int b=0;
for(int i=n;i>=1;i--){
if(i!=n){
for(int k=1;k<=b;k++){
System.out.print(" ");
}
}
for(int j=i;j>=1;j--){
System.out.print("*");
if(i!=1){
System.out.print(" ");
}
}
System.out.println();
b=b+2;
}
Output:: 5
* * * * *
* * * *
* * *
* *
*
I am learning java, using the book "Java how to program". I am solving exercises. In this actual exercise I am supposed to make a program which reads an integer from the user. The program should then display a square of asterisks (*) corresponding to the integer read from the user. F.eks user inputs the integer 3, the program should then display:
***
***
***
I try to nest a while-statement inside another, the first one to repeat the asterisks on one line, the other one to repeat this the right amount of times. Unfortunately, I only get the program to display one line. Could anyone tell me what I am doing wrong please?
The code is as follows:
import java.util.Scanner;
public class Oppgave618
{
public static void main(String[] args)
{
int numberOfSquares;
Scanner input = new Scanner(System.in);
System.out.print("Type number of asterixes to make the square: ");
numberOfSquares = input.nextInt();
int count1 = 1;
int count2 = 1;
while (count2 <= numberOfSquares)
{
while (count1 <= numberOfSquares)
{
System.out.print("*");
count1++;
}
System.out.println();
count2++;
}
}
}
You should reset count1 back in each iteration of the outer loop
public static void main(String[] args) {
int numberOfSquares;
Scanner input = new Scanner(System.in);
System.out.print("Type number of asterixes to make the square: ");
numberOfSquares = input.nextInt();
//omitted declaration of count1 here
int count2 = 1;
while (count2 <= numberOfSquares) {
int count1 = 1; //declaring and resetting count1 here
while (count1 <= numberOfSquares) {
System.out.print("*");
count1++;
}
System.out.println();
count2++;
}
}
count1 needs to be reset every time you move to the next line, e.g.
while (count2 <= numberOfSquares)
{
while (count1 <= numberOfSquares)
{
System.out.print("*");
count1++;
}
System.out.println();
count1 = 1; //set count1 back to 1
count2++;
}
Unless the exercise requires while-loops, you really should use for-loops. They will actually prevent such bugs from occurring, and require less code. Also, it is idiomatic in most programming languages to start counting from zero and use < rather than <= to terminate the loop:
for (int count2 = 0; count2 < numberOfSquares; ++count2)
{
for (int count1 = 0; count1 < numberOfSquares; ++count1)
System.out.print("*");
System.out.println();
}