PHP：if/elseif/else语句不正确的更好的方法？

-4

如何使这条if语句适用于0,1和2只猫？PHP：if/elseif/else语句不正确的更好的方法？

当回声$猫= 0或1“这是好的，你只能有2只猫”

任何代码的建议吗？

<?php 
     //If you have more then 2 cats it is illegal 
     //if you have 20 or more cats "you are a freak!" 
     //If you have 2 cats "It is fine you only have 2 cats". 
     //If you have 1 cats "It is fine you only have 1 cat". 
     //If you have 0 cats "You don't have any cats no problem". 
     $cats = 25; 
     if ($cats > 2 && $cats < 20){ 
      echo "You have too many cats, it is illegal!"; 
     } elseif ($cats >= 20) { 
      echo "you are a freak!"; 
     } elseif ($cats = 2) { 
      echo "It is fine you only have 2 cats"; 
     } elseif ($cats = 1) { 
      echo "It is fine you only have 1 cat"; 
     } elseif ($cats = 0){ 
      echo "You don't have any cats no problem"; 
     } 
    ?>

来源

2013-05-01 Josh

使用==进行比较，=是分配。

此外，考虑你的代码重新排列，以这样的：

switch($cats) { 
case 0: 
    echo "You don't have any cats"; 
    break; 
case 1: 
    echo "You have 1 cat"; 
    break; 
case 2: 
    echo "You have 2 cats"; 
    break; 
default: 
    if($cats < 20) echo "You have too many cats"; 
    else echo "You are a freak!"; 
}

来源

2013-05-01 05:09:52

是的，我只是通过CodeCademy这是明显的答案。 – Josh 2013-05-01 05:12:03

应==（比较），而不是=

} elseif ($cats == 2) {

来源

2013-05-01 05:09:10 Rikesh

啊。那也是用PHP来咬你的，呃？ – 2013-05-01 05:09:32

为什么投票？ – Rikesh 2013-05-01 05:29:50

你用错了比较运算符语法

<?php 
      //If you have more then 2 cats it is illegal 
      //if you have 20 or more cats "you are a freak!" 
      //If you have 2 cats "It is fine you only have 2 cats". 
      //If you have 1 cats "It is fine you only have 1 cat". 
      //If you have 0 cats "You don't have any cats no problem". 
      $cats = 25; 
      if ($cats > 2 && $cats < 20){ 
       echo "You have too many cats, it is illegal!"; 
      } elseif ($cats >= 20) { 
       echo "you are a freak!"; 
      } elseif ($cats == 2) { 
       echo "It is fine you only have 2 cats"; 
      } elseif ($cats == 1) { 
       echo "It is fine you only have 1 cat"; 
      } elseif ($cats == 0){ 
       echo "You don't have any cats no problem"; 
      }

来源

2013-05-01 05:09:12

有=和==之间的差异（用于分配）甚至===

检查逻辑比较图表 -

http://php.net/manual/en/language.operators.comparison.php

来源

2013-05-01 05:09:20 swapnesh

如果PHP语句需要==不等于工作。

来源

2013-05-01 05:09:22 rncrtr

好吧，除非你正在分配和测试一个真值（例如：每一个while（$ row = mysql_fetch_assoc（$ result））''循环你写过，这可能很容易就是一个'if'来测试对于单行） – 2013-05-01 15:48:07

尝试使用==代替=

else if ($cats == 2){}

来源

2013-05-01 05:10:34

错误的比较操作。只要使用它（我在你目前的编码方式与一些校正）：

<?php 
     //If you have more then 2 cats it is illegal 
     //if you have 20 or more cats "you are a freak!" 
     //If you have 2 cats "It is fine you only have 2 cats". 
     //If you have 1 cats "It is fine you only have 1 cat". 
     //If you have 0 cats "You don't have any cats no problem". 
     $cats = 25; 
    if ($cats == 0){ 
      echo "You don't have any cats no problem"; 
     }else if ($cats == 1) { 
      echo "It is fine you only have 1 cat"; 
     } else if ($cats == 2) { 
      echo "It is fine you only have 2 cats"; 
     } else if ($cats > 2 && $cats < 20){ 
      echo "You have too many cats, it is illegal!"; 
     } else { 
      echo "you are a freak!"; 
     } 
    ?>

来源

2013-05-01 05:13:09

为什么？........... – Josh 2013-05-01 05:14:10

您必须使用==代替=。使代码易于理解（将您的条件按顺序排列） – 2013-05-01 05:15:44

如果你只是用==（比较更换=（分配）您的代码可能工作 ）在您的if声明中运营商！不过，我想用switch声明往这个特定的情况下，它迄今为止更具可读性的同时向下滚动代码可以理解的;）

switch($cats) { 
    case 0: echo "You don't have any cats"; break; 
    case 1: echo "You have 1 cat"; break; 
    case 2: echo "You have 2 cats"; break; 
    default: echo ($cats < 20 ? "You have too many cats" : "You are a freak!"); 
}

的Ternary Operator谈到在这样的情况下，会非常方便的！

来源

2013-05-01 05:13:44 Ivo

PHP：if/elseif/else语句不正确的更好的方法？

回答

相关问题