08c02-1.php

介绍PHP5的给类型函数应用

<?php
// A function to format the bytes of a file, as a natural looking string.
// This version handles it via 1000 based logic:
function format_bytes($bytes) {
    // Define an array of the different display forms:
    $display = array('B', 'kB', 'MB', 'GB', 'TB', 'PB', 'EB', 'ZB', 'YB');
    
    // Now, constantly divide the value by 1000 until it is less than 1000
    $level = 0;
    while ($bytes > 1000) {
        $bytes /= 1000;
        $level++;
    }

    // Now we have our final value, format it to just 1 decimal place
    // and append on to the appropriate level moniker.
    return round($bytes, 1) . ' ' . $display[$level];
}

// Echo out a few examples to test the function:
echo '<p>4200 bytes = ', format_bytes(4200), "<p>\n"; // 4.2 kB
echo '<p>420000 bytes = ', format_bytes(420000), "<p>\n"; // 420 kB
echo '<p>42000000 bytes = ', format_bytes(42000000), "<p>\n"; // 42 MB
?>