php自定义json_encode()和json_decode()函数

if (!function_exists(‘json_encode‘)) {
function json_encode($array = array()) {
if(!is_array($array)) return null;
$json = "";
$i = 1;
$comma = ",";
$count = count($array);
foreach($array as $k=>$v){
if($i==$count) $comma = "";
if(!is_array($v)){
$v = addslashes($v);
$json .= ‘"‘.$k.‘":"‘.$v.‘"‘.$comma;
}
else{
$json .= ‘"‘.$k.‘":‘.json_encode($v).$comma;
}
$i++;
}
$json = ‘{‘.$json.‘}‘;
return $json;
}
}
if (!function_exists(‘json_decode‘)) {
function json_decode($json, $assoc = true) {
$comment = false;
$out     = ‘$x=‘;
$json = preg_replace(‘/:([^"}]+?)([,|}])/i‘, ‘:"\1″\2′, $json);
for ($i=0; $i<strlen($json); $i++) {
if (!$comment) {
if (($json[$i] == ‘{‘) || ($json[$i] == ‘[‘)) {
$out .= ‘array(‘;
}
elseif (($json[$i] == ‘}‘) || ($json[$i] == ‘]‘)) {
$out .= ‘)‘;
}
elseif ($json[$i] == ‘:‘) {
$out .= ‘=>‘;
}
elseif ($json[$i] == ‘,‘) {
$out .= ‘,‘;
}
elseif ($json[$i] == ‘"‘) {
$out .= ‘"‘;
}
}
else $out .= $json[$i] == ‘$‘ ? ‘\$‘ : $json[$i];
if ($json[$i] == ‘"‘ && $json[($i-1)] != ‘\\‘)  $comment = !$comment;
}
eval($out. ‘;‘);
return $x;
}
}