PHP Exercises: Count a substring of length 2 appears in a given string and also as the last 2 characters of the string
PHP Basic Algorithm: Exercise-31 with Solution
Write a PHP program to count a substring of length 2 appears in a given string and also as the last 2 characters of the string. Do not count the end substring.
Sample Solution:
PHP Code :
<?php
function test($s)
{
$last_two_char = substr($s, strlen($s)-2, 2);
$ctr = 0;
for ($i = 0; $i < strlen($s)-2; $i++)
{
if (substr($s, $i, 2) == $last_two_char)
$ctr = $ctr +1;
}
return $ctr;
}
echo test("abcdsab")."\n";
echo test("abcdabab")."\n";
echo test("abcabdabab")."\n";
echo test("abcabd")."\n";
Sample Output:
1 2 3 0
Pictorial Presentation:
Flowchart:
PHP Code Editor:
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Previous: Write a PHP program to create a string like "aababcabcd" from a given string "abcd".
Next: Write a PHP program to check a specified number is present in a given array of integers.
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PHP: Tips of the Day
How to Sort Multi-dimensional Array by Value?
Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:
Example:
function sortByOrder($a, $b) { return $a['order'] - $b['order']; } usort($myArray, 'sortByOrder');
Starting in PHP 5.3, you can use an anonymous function:
usort($myArray, function($a, $b) { return $a['order'] - $b['order']; });
And finally with PHP 7 you can use the spaceship operator:
usort($myArray, function($a, $b) { return $a['order'] <=> $b['order']; });
To extend this to multi-dimensional sorting, reference the second/third sorting elements if the first is zero - best explained below. You can also use this for sorting on sub-elements.
usort($myArray, function($a, $b) { $retval = $a['order'] <=> $b['order']; if ($retval == 0) { $retval = $a['suborder'] <=> $b['suborder']; if ($retval == 0) { $retval = $a['details']['subsuborder'] <=> $b['details']['subsuborder']; } } return $retval; });
If you need to retain key associations, use uasort() - see comparison of array sorting functions in the manual
Ref : https://bit.ly/3i77vCC
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