dse3168 2016-09-08 08:55
浏览 53
已采纳

在检查项目是否在数组中时,不使用array_key_exists()是否安全?

I know it's possible in PHP to check if the item is in the array this way:

if( my_array['item_one'] ){ # some code here... }

That's because if the item isn't, then null value (that equals to false or zero) is returned instead.

But will it always work? Will it always be safe to do it this way (because you know... PHP)?

  • 写回答

1条回答 默认 最新

  • dqu3974 2016-09-08 09:06
    关注

    This idiom is a bad idea. First, as noted in the comments, attempting to access a non-existent value in an array will generate an unknown index error. Second, and more important, 0 and FALSE are most definitely real values, but evaluating keys that point to such values with a snippet like you suggest will act as though they aren't there, which is just plain wrong.

    To make a long story short - PHP has an excellent tool to check if an array contains a key - array_key_exists. There's no reason not to use it.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论

报告相同问题?

悬赏问题

  • ¥15 为什么使用javacv转封装rtsp为rtmp时出现如下问题:[h264 @ 000000004faf7500]no frame?
  • ¥15 乘性高斯噪声在深度学习网络中的应用
  • ¥15 运筹学排序问题中的在线排序
  • ¥15 关于docker部署flink集成hadoop的yarn,请教个问题 flink启动yarn-session.sh连不上hadoop,这个整了好几天一直不行,求帮忙看一下怎么解决
  • ¥30 求一段fortran代码用IVF编译运行的结果
  • ¥15 深度学习根据CNN网络模型,搭建BP模型并训练MNIST数据集
  • ¥15 C++ 头文件/宏冲突问题解决
  • ¥15 用comsol模拟大气湍流通过底部加热(温度不同)的腔体
  • ¥50 安卓adb backup备份子用户应用数据失败
  • ¥20 有人能用聚类分析帮我分析一下文本内容嘛