Clever Geek Handbook

Print a star in PHP that takes one value and prints something like this

If the input signal is 3, the output should be

***
**
*
**
***

Likewise, if the accepted values ​​are 5, the output should be

*****
****
***
**
*
**
***
****
*****

This is what I did, but its not correct

<?php
echo "<pre>";
for ($row = 1; $row <= 5; $row++)
{
    for ($col = 1; $col <= 6 - $row; $col++)
    {
        echo '*';
    }

    echo "\n";
}
for ($row = 1; $row <= 5; $row++)
{
    for ($col = 1; $col <= $row; $col++)
    {
        echo '*';
    }

    echo "\n";
}
?>
+3


source to share


3 answers


What about nested loops for

?

$lineBreak = "\r\n"; // This may need to be <br /> if carriage returns don't show in <pre>
$maxNum = 5;
echo '<pre>';
for ($i = $maxNum; $i > 0; $i--) {
    echo str_repeat('*', $i) . $lineBreak;
}
for ($i = 2; $i <= $maxNum; $i++) {
    echo str_repeat('*', $i) . $lineBreak;
}
echo '</pre>';

For fun, to eliminate another loop for

:

$lineBreak = "\r\n";
$maxNum = 5;
$out = '*';
for ($i = 2; $i <= $maxNum; $i++) {
    $out = str_repeat('*', $i) . $lineBreak . $out . $lineBreak . str_repeat('*', $i);
}
echo '<pre>' . $out . '</pre>';


Please note that this code is not valid with $maxNum < 1

.

To get the value from the user, replace the string $maxNum

with ...

$maxNum = $_GET['maxNum'];

and load the page with scriptname.php?maxNum=5

+4


source


One-liner for you: p

echo implode("\n",array_map(function($n) {return str_repeat("*",$n);},array_merge(range($input,1),range(2,$input))));

Broken:



  • Create a range of numbers from "input" to 1
  • Create a range of numbers from 2 to "input" (prevents duplicate "1")
  • Combine the two ranges, resulting in a down-down list
  • Replace each element in the array with the appropriate number of stars
  • Glue them onto new lines.

Note what you may need <br />

instead \n

for browser output.

+2


source


I think your professor is looking for recursion here.

Something like this should work -

function stars($num) {
  echo str_repeat('*', $num)."\n";

  if ($num > 1) {
    stars($num - 1);
    echo str_repeat('*', $num)."\n";
  }
}
+1


source






More articles:


All Articles