取消设置数组中的项目破坏了循环数据的逻辑

我的控制器中有以下逻辑：

public function showvlans()
{
    $vlans=$this->switches_model->show_known_vlans($this->uri->segment(5), $this->uri->segment(4));
    //filter out VLAN 1 if its included in the list. 
    $key = array_search('1', $vlans);
    unset($vlans[$key]);
    header ('Content-Type: application/json; charset=UTF-8');
    echo json_encode($vlans);  

} // end showvlans  

由于某种原因，在我从数组中过滤掉一条记录后，循环 json 数据的逻辑不再起作用。

循环 json 数据的逻辑如下：

alert(returnDataFromController.length);
//loop through results
for(i = 0; i < returnDataFromController.length; i++) {
    alert(returnDataFromController[i].VlanId);
    htmlstring = htmlstring +  "<tr><td><a href=>"+returnDataFromController[i].VlanId+"</a></td><td>"+ returnDataFromController[i].Name+"</td></tr>";                         
}

Clues:

警报显示“未定义”。
我还转储了从数组中删除记录之前和之后的数据，json 数据如下所示：

删除记录之前：

[09:36:52.986] [
    {VlanId:"1", Name:"VLAN1", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"3", Name:"VLAN3", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"8", Name:"VLAN8", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"16", Name:"VLAN16", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"20", Name:"VLAN20", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"33", Name:"VLAN33", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"64", Name:"VLAN64", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"65", Name:"VLAN65", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"66", Name:"VLAN66", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"80", Name:"VLAN80", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"96", Name:"VLAN96", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"101", Name:"VLAN101", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"128", Name:"VLAN128", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"131", Name:"VLAN131", Status:"Port-based", Voice:"No", Jumbo:"No"},
    {VlanId:"417", Name:"VLAN417", Status:"Port-based", Voice:"No", Jumbo:"No"}]

AFTER:

[09:34:41.797] (
    {1:{VlanId:"3", Name:"VLAN3", Status:"Port-based", Voice:"No", Jumbo:"No"},
     2:{VlanId:"8", Name:"VLAN8", Status:"Port-based", Voice:"No", Jumbo:"No"},
     3:{VlanId:"16", Name:"VLAN16", Status:"Port-based", Voice:"No", Jumbo:"No"},
     4:{VlanId:"20", Name:"VLAN20", Status:"Port-based", Voice:"No", Jumbo:"No"},
     5:{VlanId:"33", Name:"VLAN33", Status:"Port-based", Voice:"No", Jumbo:"No"},
     6:{VlanId:"64", Name:"VLAN64", Status:"Port-based", Voice:"No", Jumbo:"No"},
     7:{VlanId:"65", Name:"VLAN65", Status:"Port-based", Voice:"No", Jumbo:"No"},
     8:{VlanId:"66", Name:"VLAN66", Status:"Port-based", Voice:"No", Jumbo:"No"},
     9:{VlanId:"80", Name:"VLAN80", Status:"Port-based", Voice:"No", Jumbo:"No"},
     10:{VlanId:"96", Name:"VLAN96", Status:"Port-based", Voice:"No", Jumbo:"No"},
     11:{VlanId:"101", Name:"VLAN101", Status:"Port-based", Voice:"No", Jumbo:"No"},
     12:{VlanId:"128", Name:"VLAN128", Status:"Port-based", Voice:"No", Jumbo:"No"},
     13:{VlanId:"131", Name:"VLAN131", Status:"Port-based", Voice:"No", Jumbo:"No"},
     14:{VlanId:"417", Name:"VLAN417", Status:"Port-based", Voice:"No", Jumbo:"No"}})

正如您所看到的，它看起来确实略有不同。我有一个空缺[在我使用 unset 之前，而在我使用之后(。 我试图改变我的循环控制，以便变量i开始于1相反...但这也不起作用。

例如，我尝试了以下操作：

for(i = 1; i < returnDataFromController.length; i++) {

代替

for(i = 0; i < returnDataFromController.length; i++) {

假设您的数组以 5 个项目开始。当所有 5 项都存在时，数组键为：0、1、2、3、4

json_encode正确地将其检测为枚举数组，并将其转换为 JSON 数组。

但是，假设您删除了索引 2 处的项目。现在，您有：0、1、3、4。json_encode看到键的非顺序编号，现在假设它是一个关联数组，因此您将返回一个键为 0、1、3、4 的 JSON 对象。JSON/Javascript 中的对象没有length，所以你的代码不再有效。

诀窍是使用array_values在将其传递给之前json_encode，如果您想将其枚举为数组。

或者，您可以更改您的for在 JavaScript 中循环：

for (var i in returnDataFromController) {
    if (returnDataFromController.hasOwnProperty(i)) {
        /* your code here */
    }
}

尽管强烈建议通过以下方式将其转换为数组array_values