for(int j = 0; j < arrayList.size(); j++) {
System.out.print(arrayList.get(j));
}
I would like to print in groups of 5, but how would the code look? Do i have to store the elements into a variable and print them that way?
How about adding a simple line break after each 5 elements?
for (int j = 0; j < arrayList.size(); j++){
System.out.print(arrayList.get(j) + " ");
if (j % 5 == 4) {
System.out.print("\n");
}
}
for(int j = 0; j < arrayList.size(); j+=5){
for (int i = 0; i < 5; i++){
//Inside this loop you can do whatever you want, concatenate...
System.out.print(arrayList.get(i+j));
}
System.out.println("");
}
You can also use the subList(int fromIndex, int toIndex) to break them.
for(int j = 0; j < arrayList.size(); j++){
if ((j != 0) && (j % 4 == 0) { System.out.println(""); }
System.out.print(arrayList.get(j));
}
Oops... Just realized lots of people answered this already...
Related
Just a simple question. I know to print all possible pairs, you do a nested for loop with a few more adjustments to be fancier. In my case, I want to take it a step up where pairs are not allowed to repeat or have 2 of the same integer in a pair.
For example: (0,0) is not allowed, but (0,1) is allowed. If (0,1) is a pair, then (1,0) is not allowed.
If I had integers "0,1,2,3", then my output would be
(0,0)(0,1)(0,2)(0,3)(1,2)(1,3)(2,3)
This is my current code that won't print pairs with 2 same integers, but repeated pairs still print.
for(int a = 0; a < 4;a++) {
numbers.add(a);
}
for(int i = 0; i < 4; i++) {
for(int j = 0; j < 4; j++) {
if(i != j) {
System.out.println("("+i+" , "+j+")");
}
}
}
Thanks
for(int i = 0; i < 4; i++) {
for(int j = i; j < 4; j++) {
if(i != j) {
System.out.println("("+i+" , "+j+")");
}
}
}
or
for(int i = 0; i < 4; i++) {
for(int j = i + 1; j < 4; j++) {
System.out.println("("+i+" , "+j+")");
}
}
I need to print a table that looks like this if the user entered a 5 using nested for loops:
****5
***45
**345
*2345
12345
I've been working on this for hours and the closest I got was:
int size = scan.nextInt();
for (int i = 1; i <= size; i++)
{
for (int star = size-1; star >= i; star--)
System.out.print("*");
for (int k = 1; k <= i; k++)
System.out.print(i);
System.out.println();
}
Which outputs this:
****1
***12
**123
*1234
12345
You have too many loops; I find it easier to reason about zero based looping so I'm going to use that. Iterate i and j from 0 to size. If j + 1 is greater than size - i - 1 then we want to print j + 1. Otherwise, we want a star. Like,
for (int i = 0; i < size; i++) {
for (int j = 0; j < size; j++) {
if (j + 1 > size - i - 1) {
System.out.print(j + 1);
} else {
System.out.print('*');
}
}
System.out.println();
}
For size = 5 that outputs (as requested)
****5
***45
**345
*2345
12345
If you simply must have one based indices, that would be
for (int i = 1; i <= size; i++) {
for (int j = 1; j <= size; j++) {
if (j > size - i) {
System.out.print(j);
} else {
System.out.print('*');
}
}
System.out.println();
}
If you want to keep your loops and avoid if statements, you can tweak last loop by changing
for (int k = 1; k <= i; k++)
into
for (int k = 1+size-i; k <= size; k++)
Btw I also find it way easier to start loops from 0, so updated code would look like this:
int size = scan.nextInt();
for (int i = 0; i < size; i++)
{
for (int star = size-1; star > i; star--)
System.out.print("*");
for (int k = size-i; k <= size; k++)
System.out.print(k);
System.out.println();
}
I hope it helps
I'm trying to create a square shape with numbers like this:
1234
2341
3412
4123
How would I go about doing that?
for (int i = 1; i <= 4; i++) {
for (int j = i; j <=4; j++) {
System.out.print(j);
}
System.out.println();
}
This prints:
1234
234
34
4
How do I get it to restart at 1 again?
You can do by using modulo
for (int i = 0; i < 4; i++) {
for (int j = 0; j < 4; j++) {
System.out.print((j + i) % 4 + 1);
}
System.out.println();
}
output
1234
2341
3412
4123
You need to update to
for (int i = 1; i <= 4; i++) {
for (int j = i; j <=4; j++) {
System.out.print(j);
}
for (int j = 1; j < i; j++) {
System.out.print(j);
}
System.out.println();
}
add one more for loop
for (int i = 1; i <= 4; i++) {
for (int j = i; j <=4; j++) {
System.out.print(j);
}
for (int j = 1; j <i; j++) {
System.out.print(j);
}
System.out.println();
}
There's probably a simpler way, but this should work:
for (int i = 1; i <= 4; i++) {
for (int j = 3; j <= 6; j++) {
System.out.print ((i + j) % 4 + 1);
}
System.out.println();
}
try this:
public class MyClass {
public static void main(String args[]) {
int count = 0;
for (int i = 1; i <= 4; i++) {
for (int j = i; j <=4; j++) {
System.out.print(j);
count += 1;
}
if(count < 4){
int remain = 4 - count; // to identify how many times it goes again
for(int k=0;k<remain;k++){
System.out.print(k+1);
}
}
count = 0;
System.out.println();
}
}
}
Output:
1234
2341
3412
4123
How about this?
for(int i = 1; i <= 4; i++){
for(int j = 1; j <= 4; j++){
System.out.print(((i + j + 2) % 4) + 1);
}
System.out.println();
}
If you look at the expected output, it has a pattern, which is restricted to a finite and known sequence of numbers. Modulus is the ideal option to handle cases like this.
for (int i = 1; i <= 4; i++) {
for (int j = 0; j <= 3; j++) {
System.out.print(((i + j) % 4) + 1);
}
System.out.println();
}
Modulus (%) gives the remainder of one number divided by another, so (i+j) % 4 always gives a result between 0 and 3.
Add one to that to get the value you want (between 1 and 4).
I am trying to make the following number line is Java
2,3,5,7,11,13,17 (Prime Numbers)
I tried this code
for(int i =0; i <= 100; i++) {
if(i < 2) {
continue;
}
for(int j = 2; j < 1; j++) {
if(i % j == 0) {
break;
} else {
System.out.print(i + ",");
}
}
}
But it doesn't work
Anyone help please?
Your code is quite poor, but the minimal amount of changes needed to make it work yields this code:
outerLoop:
for(int i = 0; i <= 100; i++) {
if(i < 2) {
continue;
}
for(int j = 2; j < i; j++) {
if(i % j == 0) {
continue outerLoop;
}
}
System.out.print(i + ",");
}
But a further improvement would be to start the first loop at 2 right away:
outerLoop:
for(int i = 2; i <= 100; i++) {
for(int j = 2; j < i; j++) {
// and so on...
EDITED
There are a lot of errors in that code, first of all that second loop is a infinite loop and second one that the System.out.println line should not be in second loop it should be at end of first loop! If you place it in second it will print numbers hundreds of time.
This is the correct code :
for(int i = 2; i <= 100; i++)//begin loop from 2 instead of 0
{
boolean flag = true;
for(int j = 2; j < i; j++)
{
if(i % j == 0)
{
flag = false;
break;
}
}
if(flag)System.out.print(i + ",");
}
You need to set a flag to check if a factor was found outside the loop.
i want to print a triangle/pyramid style like:
1
323
54345
7654567
here is my code:
int lines = 5;
for (int i = 1; i < lines; i++) {
for (int j = 1; j < lines-i; j++) {
System.out.print(" ");
}
for (int j = i; j > 1; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
for (int j = i; j < i+i; j++) {
System.out.print(j);
}
System.out.println();
}
what i got is
1
223
32345
4324567
i been studying codes while working at office and i think week long i still could not find a solution to this even i use search in Google.
i am only into enhancing my logic through conditionals and no heavy object oriented or recursion yet.
The problem in your first loop is a problem you figured out in your second one! (and it has something to do with the largest number in the loop)
for (int j = i; j > 1; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
Look at the numbers on the left of the pyramid. They start where the ones on the right end (every line of the pyramid is symmetrical). And the general formula for that number is i + i - 1, where i is the line number from your outer loop.
The second row starts at 2 * i - 1 = 2 * 2 - 1 = 3. The third row starts at 2 * 3 - 1 = 5 etc.
Your second inner loop should therefore look like this:
for (int j = i + i - 1; j > i; j--) {
System.out.print(j);
}
Here is the complete fixed source.
You have to start at the i-th odd number. This is i*2-1. And you stop at i. This also fixes a spacing difference introduced by changing it to lines = 4.
int lines = 4;
for (int i = 1; i <= lines; i++) {
for (int j = 1; j < lines-i+1; j++) {
System.out.print(" ");
}
for (int j = i*2-1; j > i; j--) { //this for loop is my problem. any solution?
System.out.print(j);
}
for (int j = i; j < i+i; j++) {
System.out.print(j);
}
System.out.println();
}
Run it here: http://ideone.com/AKsc1f
int lines = 4;
for (int i = 1; i <= lines; i++) {
for (int j = 1; j < lines-i+1; j++) {
System.out.print(" ");
}
//replace this
for(int j=0; j<i-1; j++) System.out.print(i*2-j-1);
System.out.print(i);
for(int j=; j<i-1;j++) System.out.print(i+j+1);
//==========
System.out.println();
}