PHP：如果/ elseif / else语句不正确更好的方法？ [关闭]

How do make this if statement work for 0, 1 and 2 cats?

When $cats = 0 or 1 it echos "It is fine you only have 2 cats"

Any code suggestions?

 <?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";
        }
    ?>

Use == for comparison, = is for assignment.

Additionally, consider rearranging your code to this:

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!";
}

Should be == (for comparison) and not = (for assignment)

} elseif ($cats == 2) {

you have used wrong comparison operator syntax

<?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";
            }

There is a difference between = and == and even ===

Check for the Logical Comparison chart -

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

if statements in PHP require == not = to work.

try to use == instead of =

else if ($cats == 2){}

Error on comparison operator. Just use it (I coded in your current way with some correction):

 <?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!";
        }
    ?>

Your code might work if you'd just replace the = (assignment) with == (comparison) operator within your if statements! However, I would go with a switch statement in this specific case, its by far more readable and understandable while scrolling down the code ;)

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!");
}

The Ternary Operator comes in quite handy in situations like this as well!