如果总结一下人们在这里所说的话，json_decode/encode似乎比序列化/反序列化BUT更快 如果执行var_dump，序列化对象的类型将被更改。 如果出于某种原因想要保留类型，请使用serialize!

(例如stdClass vs array)

序列化/非系列化:

Array cache:
array (size=2)
  'a' => string '1' (length=1)
  'b' => int 2
Object cache:
object(stdClass)[8]
  public 'field1' => int 123
This cache:
object(Controller\Test)[8]
  protected 'view' => 

JSON 编码/解码

Array cache:
object(stdClass)[7]
  public 'a' => string '1' (length=1)
  public 'b' => int 2
Object cache:
object(stdClass)[8]
  public 'field1' => int 123
This cache:
object(stdClass)[8]

正如你所看到的json_encode/decode将所有转换为stdClass，这不是很好，对象信息丢失…所以根据需要来决定，特别是如果它不仅仅是数组……

首先，我修改了脚本，做了更多的基准测试(也做了1000次而不是1次):

<?php

ini_set('display_errors', 1);
error_reporting(E_ALL);

// Make a big, honkin test array
// You may need to adjust this depth to avoid memory limit errors
$testArray = fillArray(0, 5);

$totalJsonTime = 0;
$totalSerializeTime = 0;
$totalJsonWins = 0;

for ($i = 0; $i < 1000; $i++) {
    // Time json encoding
    $start = microtime(true);
    $json = json_encode($testArray);
    $jsonTime = microtime(true) - $start;
    $totalJsonTime += $jsonTime;

    // Time serialization
    $start = microtime(true);
    $serial = serialize($testArray);
    $serializeTime = microtime(true) - $start;
    $totalSerializeTime += $serializeTime;

    if ($jsonTime < $serializeTime) {
        $totalJsonWins++;
    }
}

$totalSerializeWins = 1000 - $totalJsonWins;

// Compare them
if ($totalJsonTime < $totalSerializeTime) {
    printf("json_encode() (wins: $totalJsonWins) was roughly %01.2f%% faster than serialize()\n", ($totalSerializeTime / $totalJsonTime - 1) * 100);
} else {
    printf("serialize() (wins: $totalSerializeWins) was roughly %01.2f%% faster than json_encode()\n", ($totalJsonTime / $totalSerializeTime - 1) * 100);
}

$totalJsonTime = 0;
$totalJson2Time = 0;
$totalSerializeTime = 0;
$totalJsonWins = 0;

for ($i = 0; $i < 1000; $i++) {
    // Time json decoding
    $start = microtime(true);
    $orig = json_decode($json, true);
    $jsonTime = microtime(true) - $start;
    $totalJsonTime += $jsonTime;

    $start = microtime(true);
    $origObj = json_decode($json);
    $jsonTime2 = microtime(true) - $start;
    $totalJson2Time += $jsonTime2;

    // Time serialization
    $start = microtime(true);
    $unserial = unserialize($serial);
    $serializeTime = microtime(true) - $start;
    $totalSerializeTime += $serializeTime;

    if ($jsonTime < $serializeTime) {
        $totalJsonWins++;
    }
}

$totalSerializeWins = 1000 - $totalJsonWins;


// Compare them
if ($totalJsonTime < $totalSerializeTime) {
    printf("json_decode() was roughly %01.2f%% faster than unserialize()\n", ($totalSerializeTime / $totalJsonTime - 1) * 100);
} else {
    printf("unserialize() (wins: $totalSerializeWins) was roughly %01.2f%% faster than json_decode()\n", ($totalJsonTime / $totalSerializeTime - 1) * 100);
}

// Compare them
if ($totalJson2Time < $totalSerializeTime) {
    printf("json_decode() was roughly %01.2f%% faster than unserialize()\n", ($totalSerializeTime / $totalJson2Time - 1) * 100);
} else {
    printf("unserialize() (wins: $totalSerializeWins) was roughly %01.2f%% faster than array json_decode()\n", ($totalJson2Time / $totalSerializeTime - 1) * 100);
}

function fillArray( $depth, $max ) {
    static $seed;
    if (is_null($seed)) {
        $seed = array('a', 2, 'c', 4, 'e', 6, 'g', 8, 'i', 10);
    }
    if ($depth < $max) {
        $node = array();
        foreach ($seed as $key) {
            $node[$key] = fillArray($depth + 1, $max);
        }
        return $node;
    }
    return 'empty';
}

我使用PHP 7的这个版本:

PHP 7.0.14 (cli)(已构建:2017年1月18日19:13:23)(NTS)版权所有(c) PHP Group Zend Engine v3.0.0，版权所有(c) 1998-2016 Zend技术 与Zend OPcache v7.0.14，版权(c) 1999-2016，由Zend Technologies

我的结果是:

Serialize()(胜:999)比json_encode()快大约10.98% Unserialize()(胜:987)大约比json_decode()快33.26% Unserialize()(胜:987)大约比array快48.35% json_decode ()

显然，序列化/反序列化是最快的方法，而json_encode/decode是最可移植的方法。

如果您考虑这样一个场景:您读/写序列化数据的次数是向非php系统发送数据或从非php系统接收数据的次数的10倍或更多，那么就时间而言，最好还是使用序列化/反序列化，并在序列化之前使用json_encode或json_decode。

我曾经写过一篇关于这个主题的博文:“缓存一个大数组:JSON，序列化还是var_export?”在这篇文章中，我们展示了序列化是大小数组的最佳选择。对于非常大的数组(> 70MB)， JSON是更好的选择。

我知道这有点晚了，但答案很旧，我想我的基准测试可能会有帮助，因为我刚刚在PHP 7.4中测试过

Serialize/Unserialize比JSON快得多，占用的内存和空间更少，在PHP 7.4中完全胜出，但我不确定我的测试是最有效或最好的。

我基本上创建了一个PHP文件，它返回一个数组，我编码，序列化，然后解码和反序列化。

$array = include __DIR__.'/../tests/data/dao/testfiles/testArray.php';

//JSON ENCODE
$json_encode_memory_start = memory_get_usage();
$json_encode_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $encoded = json_encode($array);
}

$json_encode_time_end = microtime(true);
$json_encode_memory_end = memory_get_usage();
$json_encode_time = $json_encode_time_end - $json_encode_time_start;
$json_encode_memory = 
$json_encode_memory_end - $json_encode_memory_start;


//SERIALIZE
$serialize_memory_start = memory_get_usage();
$serialize_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $serialized = serialize($array);
}

$serialize_time_end = microtime(true);
$serialize_memory_end = memory_get_usage();
$serialize_time = $serialize_time_end - $serialize_time_start;
$serialize_memory = $serialize_memory_end - $serialize_memory_start;


//Write to file time:
$fpc_memory_start = memory_get_usage();
$fpc_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $fpc_bytes = 
    file_put_contents(
        __DIR__.'/../tests/data/dao/testOneBigFile',
        '<?php return '.var_export($array,true).' ?>;'
    );
}

$fpc_time_end = microtime(true);
$fpc_memory_end = memory_get_usage();
$fpc_time = $fpc_time_end - $fpc_time_start;
$fpc_memory = $fpc_memory_end - $fpc_memory_start;


//JSON DECODE
$json_decode_memory_start = memory_get_usage();
$json_decode_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $decoded = json_encode($encoded);
}

$json_decode_time_end = microtime(true);
$json_decode_memory_end = memory_get_usage();
$json_decode_time = $json_decode_time_end - $json_decode_time_start;
$json_decode_memory = 
$json_decode_memory_end - $json_decode_memory_start;


//UNSERIALIZE
$unserialize_memory_start = memory_get_usage();
$unserialize_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $unserialized = unserialize($serialized);
}

$unserialize_time_end = microtime(true);
$unserialize_memory_end = memory_get_usage();
$unserialize_time = $unserialize_time_end - $unserialize_time_start;
$unserialize_memory = 
$unserialize_memory_end - $unserialize_memory_start;


//GET FROM VAR EXPORT:
$var_export_memory_start = memory_get_usage();
$var_export_time_start = microtime(true);

for ($i=0; $i < 20000; $i++) { 
    $array = include __DIR__.'/../tests/data/dao/testOneBigFile';
}

$var_export_time_end = microtime(true);
$var_export_memory_end = memory_get_usage();
$var_export_time = $var_export_time_end - $var_export_time_start;
$var_export_memory = $var_export_memory_end - $var_export_memory_start;

结果:

Var输出长度:11447 序列化长度:11541 Json编码长度:11895 文件放内容字节:11464

Json编码时间:1.9197590351105 序列化时间:0.160325050354 FPC时间:6.2793469429016

Json编码内存:12288 序列化内存:12288 FPC内存:0

JSON解码时间:1.7493588924408 UnSerialize Time: 0.19309520721436 Var导出和包括:3.1974139213562

JSON解码内存:16384 反序列化内存:14360 Var Export and Include: 192

似乎serialize是我要使用的一个，有两个原因:

有人指出，unserialize比json_decode更快，而且'read' case听起来比'write' case更有可能。 当使用无效UTF-8字符的字符串时，我遇到了json_encode的问题。当这种情况发生时，字符串最终为空，导致信息丢失。

我已经在一个相当复杂、嵌套简单、包含各种数据(字符串、NULL、整数)的多散列上对此进行了非常彻底的测试，序列化/反序列化最终比json_encode/json_decode快得多。

在我的测试中，json的唯一优势是它的“打包”大小更小。

这些都是在PHP 5.3.3下完成的，如果你想了解更多细节，请告诉我。

下面是测试结果，然后是生成它们的代码。我不能提供测试数据，因为它会泄露一些我不能公开的信息。

JSON encoded in 2.23700618744 seconds
PHP serialized in 1.3434419632 seconds
JSON decoded in 4.0405561924 seconds
PHP unserialized in 1.39393305779 seconds

serialized size : 14549
json_encode size : 11520
serialize() was roughly 66.51% faster than json_encode()
unserialize() was roughly 189.87% faster than json_decode()
json_encode() string was roughly 26.29% smaller than serialize()

//  Time json encoding
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    json_encode( $test );
}
$jsonTime = microtime( true ) - $start;
echo "JSON encoded in $jsonTime seconds<br>";

//  Time serialization
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    serialize( $test );
}
$serializeTime = microtime( true ) - $start;
echo "PHP serialized in $serializeTime seconds<br>";

//  Time json decoding
$test2 = json_encode( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    json_decode( $test2 );
}
$jsonDecodeTime = microtime( true ) - $start;
echo "JSON decoded in $jsonDecodeTime seconds<br>";

//  Time deserialization
$test2 = serialize( $test );
$start = microtime( true );
for($i = 0; $i < 10000; $i++) {
    unserialize( $test2 );
}
$unserializeTime = microtime( true ) - $start;
echo "PHP unserialized in $unserializeTime seconds<br>";

$jsonSize = strlen(json_encode( $test ));
$phpSize = strlen(serialize( $test ));

echo "<p>serialized size : " . strlen(serialize( $test )) . "<br>";
echo "json_encode size : " . strlen(json_encode( $test )) . "<br></p>";

//  Compare them
if ( $jsonTime < $serializeTime )
{
    echo "json_encode() was roughly " . number_format( ($serializeTime / $jsonTime - 1 ) * 100, 2 ) . "% faster than serialize()";
}
else if ( $serializeTime < $jsonTime )
{
    echo "serialize() was roughly " . number_format( ($jsonTime / $serializeTime - 1 ) * 100, 2 ) . "% faster than json_encode()";
} else {
    echo 'Unpossible!';
}
    echo '<BR>';

//  Compare them
if ( $jsonDecodeTime < $unserializeTime )
{
    echo "json_decode() was roughly " . number_format( ($unserializeTime / $jsonDecodeTime - 1 ) * 100, 2 ) . "% faster than unserialize()";
}
else if ( $unserializeTime < $jsonDecodeTime )
{
    echo "unserialize() was roughly " . number_format( ($jsonDecodeTime / $unserializeTime - 1 ) * 100, 2 ) . "% faster than json_decode()";
} else {
    echo 'Unpossible!';
}
    echo '<BR>';
//  Compare them
if ( $jsonSize < $phpSize )
{
    echo "json_encode() string was roughly " . number_format( ($phpSize / $jsonSize - 1 ) * 100, 2 ) . "% smaller than serialize()";
}
else if ( $phpSize < $jsonSize )
{
    echo "serialize() string was roughly " . number_format( ($jsonSize / $phpSize - 1 ) * 100, 2 ) . "% smaller than json_encode()";
} else {
    echo 'Unpossible!';
}