Php 拉威尔未定义偏移量：1451

我试图将从数据库中获取的一些元素作为集合汇总到新创建的数组中，代码如下所示

foreach ($demands as $demand) {

    $demandProject[$demand->projectid][$demand->week]['tickets'] += isset($demand->title) ? $demand->title : '';
    $demandProject[$demand->projectid][$demand->week]['total']   += (float) $demand->time;
    $demandProject[$demand->projectid][$demand->week]['l1']      += $demand->time_l1;
    $demandProject[$demand->projectid][$demand->week]['l2']      += $demand->time_l2;
    $demandProject[$demand->projectid][$demand->week]['l3']      += $demand->time_l3;
    $demandProject[$demand->projectid][$demand->week]['l4']      += $demand->time_l4;
    $demandProject[$demand->projectid][$demand->week]['l5']      += $demand->time_l5;
    $demandProject[$demand->projectid][$demand->week]['ns']      += $demand->time_ns;
}

但是我越来越

ErrorException
Undefined offset: 1451

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这个错误意味着我做错了什么

您需要处理错误-代码过于乐观<代码>如果（isset（$demandProject[$demand->projectid]）和isset（$demandProject[$demand->projectid][$demand->week]）。。。否则…感谢我之间的反馈，如果未定义索引，我必须添加起始值。是的，您需要处理错误-代码过于乐观<代码>如果（isset（$demandProject[$demand->projectid]）和isset（$demandProject[$demand->projectid][$demand->week]）。。。否则…感谢您的反馈，如果尚未定义索引，我必须添加起始值