How to print this Pattern?
$number = 5;
for ($i=1; $i <= $number ; $i++) {
for ($j=$i; $j >= 1;$j--){
echo "0";
}
echo "\n";
}
Prints
0
00
000
0000
00000
I've tries like this, but i'm confused to print star and Zero char
for ($i=1; $i <= $number ; $i++) {
$sum = 0;
for ($j=$i; $j >= 1;$j--){
$sum +=$j;
}
echo $i ." => " .$sum ."\n";
}
Prints
1 => 1
2 => 3
3 => 6
4 => 10
5 => 15
You can use str_repeat to generate the strings of required length. Note that for triangular numbers (1, 3, 6, 10, 15, ...) you can generate the i'th number as i(i+1)/2:
$number = 5;
for ($i = 1; $i <= $number; $i++) {
echo str_repeat('*', $i * ($i + 1) /2) . str_repeat('0', $i) . PHP_EOL;
}
Output:
*0
***00
******000
**********0000
***************00000
For a more literal generation of the triangular part of the output (i.e. sum of the numbers from 1 to i), you could use this code which adds $i *'s and 1 0 to the output on each iteration:
$line = '';
$number = 5;
for ($i = 1; $i <= $number; $i++) {
$line = str_repeat('*', $i) . $line . '0';
echo $line . PHP_EOL;
}
Output:
*0
***00
******000
**********0000
***************00000
Here is another way, which uses a more literal reading of the replacement logic. Here, I form each subsequent line by taking the previous line, and adding the line number amount of * to the * section, and then just tag on a new trailing zero.
$line = "*0";
$max = 5;
$counter = 1;
do {
echo $line . "\n";
$line = preg_replace("/(\*+)/", "\\1" . str_repeat("*", ++$counter), $line) . "0";
} while ($counter <= $max);
This prints:
*0
***00
******000
**********0000
***************00000
The number of zeros are equal to $i in the for loop. So we just need to calculate the number of stars and then simply do a str_repeat
$count = 5;
for ($i=1; $i <= $count; $i++) {
$stars = 0;
for($j=1; $j <= $i; $j++) {
$stars = $stars + $j;
}
echo str_repeat('*', $stars).str_repeat('0', $i)."\n";
}
Output:
*0
***00
******000
**********0000
***************00000
$line = '';
for ($i = 1; $i <= 5; $i++) {
$line = str_repeat('*', $i) . $line . '0'; // **str_repeat()** --> getting string length
echo $line . PHP_EOL; // **PHP_EOL** ---> represents the endline character.
}