PHP:If/elseif/else语句不正确更好的方法？

如何使此if语句适用于0、1和2猫

当$cats=0或1时，它会回显“很好，您只有2只猫”

有代码建议吗

 <?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";
        }
    ?>

应该是
=
（用于比较）而不是
=
（用于分配）

您使用了错误的比较运算符语法

<?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";
            }

在
=
和
=
之间甚至
==

检查逻辑比较图表-

如果PHP中的语句要求==不=工作。
使用
==
进行比较，
=
用于赋值

另外，考虑将代码重新排列为：
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!";
}

开关（$cats）{
案例0：
echo“你没有猫”；
打破
案例1：
回声“你有一只猫”；
打破
案例2：
回声“你有两只猫”；
打破
违约：
如果（$cats<20）回应“你有太多的猫”；
否则我会回应“你是个怪胎！”；
}
尝试使用
=
而不是
=

else if（$cats==2）{}
比较运算符出错。只需使用它（我以您当前的方式编码，并进行了一些更正）：

如果在
if
语句中用=（赋值）操作符替换=（比较）操作符，代码可能会工作！但是，在这种情况下，我会使用一个语句，在向下滚动代码时，它的可读性和可理解性要高得多；）

开关（$cats）{
案例0：呼应“你没有猫”；休息；
案例1：回显“你有一只猫”；中断；
案例2：呼应“你有两只猫”；休息；
默认值：echo（$cats<20？）：“你的猫太多了”：“你是个怪胎！”；
}

在类似这样的情况下，这种方法也非常方便
 啊。这在PHP中也会让你头疼，是吗？是的，我正在浏览CodeCademy这是显而易见的答案。你必须使用==而不是=。使代码易于理解（将您的条件按顺序排列），除非您正在分配和测试一个真实值（例如：every
while（$row=mysql\u fetch\u assoc（$result））
您曾经编写过的循环，它可以很容易地成为一个
if
测试一行）
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!";
}

 <?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!";
        }
    ?>

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!");
}