PHP Array Exercises : Check whether all array values are strings or not

Last update on May 30 2022 11:40:44 (UTC/GMT +8 hours)

PHP Array: Exercise-46 with Solution

Write a PHP function to check whether all array values are strings or not.

Sample Solution:

PHP Code:

<?php
function check_strings_in_array($arr) 
{
    return array_sum(array_map('is_string', $arr)) == count($arr);
}
$arr1 = array('PHP', 'JS', 'Python');
$arr2 = array('SQL', 200, 'MySQL');
var_dump(check_strings_in_array($arr1));
var_dump(check_strings_in_array($arr2));
?>

Sample Output:

bool(true)                                                  
bool(false)

Flowchart:

PHP Code Editor:

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Previous: Write a PHP script to do a multi-dimensional difference, i.e. returns values of the first array that are not in the second array.
Next: Write a PHP function to get an array with the first key and value.

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