ajax返回json格式数据

控制器中这样写

//删除二维码
public function shanchu()
{

    $data = $_POST['a'];
    $shanchu = K::M('code/content')->shanchu($data);
    $returnData = json_encode($shanchu, JSON_UNESCAPED_UNICODE); 
    // var_dump($shanchu);
    // var_dump($returnData);
    // echo '111';
    // die;
    echo $returnData;
    exit;
}

打印出来是下面这个

array(2) {
[“code”]=>
int(3)
[“info”]=>
string(12) “删除成功”
}
string(32) “{“code”:3,“info”:“删除成功”}”

模型中这样写

//删除二维码
public function shanchu(KaTeX parse error: Expected '}', got 'EOF' at end of input: …{ if (!data) {
$returnData = [‘code’=>1, ‘info’=>‘数据错误’];
} else {
$data = $this->chaxun('code',$data);
if (KaTeX parse error: Expected '}', got 'EOF' at end of input: … foreach (data as $v) {
$data = $v;
}
$succ = $this->update($v[‘id’], [‘status’=>0], 1);
if ($succ) {
$returnData = [‘code’=>3, ‘info’=>‘删除成功’];
} else {
$returnData = [‘code’=>4, ‘info’=>‘删除失败’];
}
} else {
$returnData = [‘code’=>2, ‘info’=>‘二维码不存在’];
}
}

    return $returnData;
}

html 页面中