Question

我搜索了google和堆栈溢出论坛，他们反复说使用isset（）来确保定义索引，但是如果没有设置索引，很少有人知道该怎么做。

这是我的简单代码：

<?php
    $allStaff = $this->registry->getData('staff');
    $departments = array();
    foreach($allStaff as $staff){
        if(isset($departments[$staff['department']])){
            $departments[$staff['department']][count($departments[$staff['department']])] = $staff;
        }
        else {
            $departments[$staff['department']][count($departments[$staff['department']])] = $staff;
        }

idexing系统的一个例子是：$ departments [＆＃39; Management＆＃39;] [0] [＆＃39; name / staff position / etc＆＃39;]

在我查看其他用户的一些答案时，我尝试过设置$ department [$ staff [＆＃39; department＆＃39;]] = 0，但它不起作用并且给我带来更多错误。请帮助，谢谢

Answer 1

它会给你带来问题的地方在这里：

count($departments[$staff['department']])

因此，您要确保为其分配了兼容性，然后您可以使用它：

if (!isset($departments[$staff['department']]))
    $departments[$staff['department']] = array();

$departments[$staff['department']][count($departments[$staff['department']])] = $staff;

PHP将默认为您处理顺序数字索引，因此您可以将上述内容简化为（感谢BNC的灵感）：

if (!isset($departments[$staff['department']]))
    $departments[$staff['department']] = array();

$departments[$staff['department']][] = $staff;

请注意，您的代码有P[Q[i]][j] = Q这样的模式，可以正常工作，只是不经常看到。

Answer 2

目前还不清楚你在这里要做什么。我猜你想要计算每个部门有多少工作人员。如果我猜错了，请用英文（不是代码）说出你的目标。如果我的猜测是正确的，......

$allStaff = $this->registry->getData('staff');
$departments = array();
foreach($allStaff as $staff){
    if( !isset($departments[$staff['department']]) ) {
        $departments[$staff['department']] = 0;
    }
    $departments[$staff['department']] += 1;
}

更新：等等，我想我只是想通了（当count()足以附加到数组时，我被[]误导了。我现在猜你想要按部门分组的工作人员......

$allStaff = $this->registry->getData('staff');
$departments = array();
foreach($allStaff as $staff){
    if( !isset($departments[$staff['department']]) ) {
        $departments[$staff['department']] = array();
    }
    $departments[$staff['department']][] = $staff;
}

php array undefined index

2 个答案: