PHP Challenges: Find the single number which occurs odd number of times and other numbers occur even number of times

Last update on May 30 2022 11:44:02 (UTC/GMT +8 hours)

PHP Challenges - 1: Exercise-25 with Solution

Write a PHP program to find the single number which occurs odd number of times and other numbers occur even number of times.

Input : 4, 5, 4, 5, 2, 2, 3, 3, 2, 4, 4

Explanation :

PHP: find the single number which occurs odd numbers and other numbers occur even number.

Sample Solution :

PHP Code :

<?php
function odd_occurrence($arr)
{
    $result = 0;
     
    # Traverse the array
    foreach ($arr as &$value)
    {
        # Xor (exclusive or)
        # Bits that are set in $a or $b but not both are set.
        $result = $result ^ $value;
    }
    return $result;
}
$num1 = array(4, 5, 4, 5, 2, 2, 3, 3, 2, 4, 4);
print_r(odd_occurrence($num1)."\n");
?>

Sample Output:

Flowchart:

PHP Code Editor:

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Previous: Write a PHP program to find the length of the last word in a string.

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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