function convertToReadableSize($size)
{
  $base = log($size) / log(1024);
  $suffix = array("B", "KB", "MB", "GB", "TB");
  $f_base = floor($base);
  return round(pow(1024, $base - floor($base)), 1) . $suffix[$f_base];
}

只需要调用函数

echo convertToReadableSize(1024); // Outputs '1KB'
echo convertToReadableSize(1024 * 1024); // Outputs '1MB'

虽然有点陈旧，这个库提供了一个经过测试的和健壮的转换API:

https://github.com/gabrielelana/byte-units

一旦安装:

\ByteUnits\Binary::bytes(1024)->format();

// Output: "1.00KiB"

并向另一个方向转换:

\ByteUnits\Binary::parse('1KiB')->numberOfBytes();

// Output: "1024"

除了基本的转换，它还提供了加法、减法、比较等方法。

我决不是这家图书馆的会员。

下面是一个使用log10的选项:

<?php

function format_number(float $d): string {
   $e = (int)(log10($d) / 3);
   return sprintf('%.3f', $d / 1e3 ** $e) . ['', ' k', ' M', ' G'][$e];
}

$s = format_number(9012345678);
var_dump($s == '9.012 G');

https://php.net/function.log10

kb除以1024,mb除以1024^2,GB除以1024^3。就这么简单。

function changeType($size, $type, $end){
    $arr = ['B', 'KB', 'MB', 'GB', 'TB'];
    $tSayi = array_search($type, $arr);
    $eSayi = array_search($end, $arr);
    $pow = $eSayi - $tSayi;
    return $size * pow(1024 * $pow) . ' ' . $end;
}

echo changeType(500, 'B', 'KB');

灵活的解决方案:

function size($size, array $options=null) {

    $o = [
        'binary' => false,
        'decimalPlaces' => 2,
        'decimalSeparator' => '.',
        'thausandsSeparator' => '',
        'maxThreshold' => false, // or thresholds key
        'suffix' => [
            'thresholds' => ['', 'K', 'M', 'G', 'T', 'P', 'E', 'Z', 'Y'],
            'decimal' => ' {threshold}B',
            'binary' => ' {threshold}iB',
            'bytes' => ' B'
        ]
    ];

    if ($options !== null)
        $o = array_replace_recursive($o, $options);

    $base = $o['binary'] ? 1024 : 1000;
    $exp = $size ? floor(log($size) / log($base)) : 0;

    if (($o['maxThreshold'] !== false) &&
        ($o['maxThreshold'] < $exp)
    )
        $exp = $o['maxThreshold'];

    return !$exp
        ? (round($size) . $o['suffix']['bytes'])
        : (
            number_format(
                $size / pow($base, $exp),
                $o['decimalPlaces'],
                $o['decimalSeparator'],
                $o['thausandsSeparator']
            ) .
            str_replace(
                '{threshold}',
                $o['suffix']['thresholds'][$exp],
                $o['suffix'][$o['binary'] ? 'binary' : 'decimal']
            )
        );
}

var_dump(size(disk_free_space('/')));
// string(8) "14.63 GB"
var_dump(size(disk_free_space('/'), ['binary' => true]));
// string(9) "13.63 GiB"
var_dump(size(disk_free_space('/'), ['maxThreshold' => 2]));
// string(11) "14631.90 MB"
var_dump(size(disk_free_space('/'), ['binary' => true, 'maxThreshold' => 2]));
// string(12) "13954.07 MiB"