douhua1890 2016-06-30 16:23
浏览 847
已采纳

具有多种条件的三元运算符

Hello I am trying to properly format ternary operator to be using multiple conditions in php:

$result = ($var !== 1 || $var !== 2) ? '' : 'default';

The problem is that in this format I always get not true even iv the $var is 1 or 2. With one condition for example $var == 0 it is working fine. Any help will be welcome.

  • 写回答

2条回答

  • dongwubao4785 2016-06-30 16:26
    关注

    This statement will always be true:

    ($var !== 1 || $var !== 2)
    

    Because $var can never simultaneously be both values, it will always not be at least one of the two values. Which satisfies the || operator.

    If you want to know whether $var is one of the two values:

    ($var === 1 || $var === 2)
    

    If you want to know if $var is neither of the two values, you can negate the condition:

    (!($var === 1 || $var === 2))
    

    Or individually negate the operators in the condition and use && instead of || (since all conditions need to be met to prove the negative, instead of just one condition to prove the positive):

    ($var !== 1 && $var !== 2)
    

    Depending on readability and personal preference.

    本回答被题主选为最佳回答 , 对您是否有帮助呢?
    评论
查看更多回答(1条)

报告相同问题?

悬赏问题

  • ¥15 YoloV5 第三方库的版本对照问题
  • ¥15 请完成下列相关问题!
  • ¥15 drone 推送镜像时候 purge: true 推送完毕后没有删除对应的镜像,手动拷贝到服务器执行结果正确在样才能让指令自动执行成功删除对应镜像,如何解决?
  • ¥15 求daily translation(DT)偏差订正方法的代码
  • ¥15 js调用html页面需要隐藏某个按钮
  • ¥15 ads仿真结果在圆图上是怎么读数的
  • ¥20 Cotex M3的调试和程序执行方式是什么样的?
  • ¥20 java项目连接sqlserver时报ssl相关错误
  • ¥15 一道python难题3
  • ¥15 牛顿斯科特系数表表示