php - PHP Parse 错误：语法错误，第 14 行出现意外的“[”

Question

我尝试运行代码，但检测到错误。关于数组二维的错误“PHP Parse error: syntax error, unexpected '['”。我对编程还是新手，你们能帮忙看看我的代码有什么问题吗？

$relationships = [
    ['id' => '86', 'sender' => '...', 'receiver' => '...', 'docType' => 'Report'],
    ['id' => '687', 'sender' => '...', 'receiver' => '...', 'docType' => 'Invoice'],
    ['id' => '1064', 'sender' => '...', 'receiver' => '...', 'docType' => 'Invoice'],

];