Please note, this is a STATIC archive of website www.w3resource.com from 19 Jul 2022, cach3.com does not collect or store any user information, there is no "phishing" involved.
w3resource

PHP Exercises: Check if the first appearance of "a" in a given string is immediately followed by another "a"

PHP Basic Algorithm: Exercise-28 with Solution

Write a PHP program to check if the first appearance of "a" in a given string is immediately followed by another "a".

Sample Solution:

PHP Code :

<?php
function test($s)
{
   $counter = 0;
            for ($i = 0; $i < strlen($s)-1; $i++)
            {
                if (substr($s, $i, 1) == 'a') $counter++;
                if ((substr($s, $i, 2) == 'aa') && $counter < 2) 
                return true;
            }
            return false;
 }

var_dump(test("caabb"));
var_dump(test("babaaba"));
var_dump(test("aaaaa"));

Sample Output:

bool(true)
bool(false)
bool(true)

Pictorial Presentation:

PHP Basic Algorithm Exercises: Check if the first appearance of 'a' in a given string is immediately followed by another 'a'.

Flowchart:

Flowchart: Check if the first appearance of 'a' in a given string is immediately followed by another 'a'.

PHP Code Editor:

Contribute your code and comments through Disqus.

Previous: Write a PHP program to count the string "aa" in a given string and assume "aaa" contains two "aa".
Next: Write a PHP program to create a new string made of every other character starting with the first from a given string.

What is the difficulty level of this exercise?

Test your Programming skills with w3resource's quiz.



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