php相关有关问题，高手帮忙讲解一下原理

php相关问题，高手帮忙讲解一下原理
为什么url编码后，然后再解码就不会出现‘\u51b0\u706b\u56fd\u5ea6’这类字符呢？

PHP code

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-->
<?php $data = array(
‘game’ => ‘冰火国度’,
‘name’ =>  ‘刺之灵’,
‘country’ => ‘冰霜国’,
‘level’ => 45
);
echo json_encode( $data );
echo ‘<br>’;
/**
* 处理json_encode乱码
*/
$newData = array();
foreach( $data as $key => $value )
{
$newData[ $key ] = urlencode( $value );
}
echo urldecode( json_encode( $newData ) );
?>

结果显示：
{“game”:”\u51b0\u706b\u56fd\u5ea6″,”name”:”\u523a\u4e4b\u7075″,”country”:”\u51b0\u971c\u56fd”,”level”:45}
{“game”:”冰火国度”,”name”:”刺之灵”,”country”:”冰霜国”,”level”:”45″}

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