05c04-1.php

来自「介绍PHP5的给类型函数应用」· PHP 代码 · 共 60 行

<?php
//  Create a nested array structure
$scores = array (
    'Siegfried' => array(117, 72, 53.3),
    'Francesca' => array(84.7),
    'Jonathas' => array(96.7, 37),
    'Mika' => array(113, 100, 81),
    'Timothy' => array(80.7, 80.3),
    );

// Create a function that will sort based upon the length of the subarray
function compare_length($a, $b) {
    // For each look at the length of the subarray
    $a_length = count($a);
    $b_length = count($b);
    
    // If they are the same, return 0
    if ($a_length == $b_length) {
        return 0;
    } else {
        // See which one is bigger
        return ($a_length > $b_length) ? -1 : 1;
    }
}

// Using that formula, sort the array, keeping the key associations intact:
uasort($scores, 'compare_length');

// Echo out the keys in their new order ... Will be in order:
// Mika, Siegfried, Timothy, Jonathas, Francesca
echo '<pre>';
echo "Sorted by array length: \n";
print_r(array_keys($scores));
echo "\n\n";

// Create a function to sort them by the maximum value in the subarray
function compare_max($a, $b) {
    // Take a look a the maximum values:
    $a_max = max($a);
    $b_max = max($b);
    
    // If they are the same, return 0
    if ($a_max == $b_max) {
        return 0;
    } else {
        // See which one is bigger
        return ($a_max > $b_max) ? -1 : 1;
    }
}

// Resort the array by maximum value:
uasort($scores, 'compare_max');

// Echo out the keys now sorted by max ... Will be in order:
// Siegfried, Mika, Jonathas, Francesca, Timothy
echo "Sorted by array maximum value: \n";
print_r(array_keys($scores));
echo '</pre>';
?>