PHP Exercises: Create a new string which is 4 copies of the 2 front characters of a given string
PHP Basic Algorithm: Exercise-8 with Solution
Write a PHP program to create a new string which is 4 copies of the 2 front characters of a given string. If the given string length is less than 2 return the original string.
Sample Solution:
PHP Code :
<?php
function test($str)
{
return strlen($str) < 2 ? $str : substr($str, 0, 2).substr($str, 0, 2).substr($str, 0, 2).substr($str, 0, 2);
}
echo test("C Sharp")."\n";
echo test("JS")."\n";
echo test("a")."\n";
Sample Output:
C C C C JSJSJSJS a
Pictorial Presentation:
Flowchart:
PHP Code Editor:
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Previous: Write a PHP program to exchange the first and last characters in a given string and return the new string.
Next: Write a PHP program to create a new string with the last char added at the front and back of a given string of length 1 or more.
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PHP: Tips of the Day
How to Sort Multi-dimensional Array by Value?
Try a usort, If you are still on PHP 5.2 or earlier, you'll have to define a sorting function first:
Example:
function sortByOrder($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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