Question

我正在尝试编写一个简单的do / while语句，它创建一个随机数，然后检查该数字是否低于某个阈值，如果是，则应该停止while循环。然而它似乎并不适合我，我无法弄清楚为什么。

我猜它会变得非常简单，但我现在还不知道。

这是我的代码，非常感谢帮助！

<!DOCTYPE html>
<html>
    <head>
        <title>Your own do-while</title>
        <link type='text/css' rel='stylesheet' href='style.css'/>
    </head>
    <body>
    <?php
    $rayBans = rand(0,70);
    $correctPrice = false;
    do {
        echo "<p> Lets hope I can get ray bans for under £30! </p>";
    }
    while ($correctPrice == false);
        if ($rayBans > 30) {
        echo "<p> raybans at $rayBans are too expensive </p>";
        $correctPrice == false;
    }
    else if ($rayBans < 30){
        echo "<p> Finaly got my rayBans for $rayBans </p>";
        $correctPrice == true;
    }


    ?>
    </body>
</html>

Answer 1

在比较时我们应该使用==，同时将值分配给变量，我们需要=，所以在您的情况下

do 
{
//You should write something so that $correctPrice becomes true
//as of now it seems to be a infinite loop
echo "<p> Lets hope I can get ray bans for under £30! </p>";
}while ($correctPrice == false);

我相信你需要这样做

<?php
    $correctPrice = false;
    do 
    {
        $rayBans = rand(0,70);
        echo "<p> Lets hope I can get ray bans for under £30! </p>";
        if ($rayBans > 30) 
        {
            echo "<p> raybans at $rayBans are too expensive </p>";
            $correctPrice = false;
        }
        else if ($rayBans < 30)
        {
            echo "<p> Finaly got my rayBans for $rayBans </p>";
            $correctPrice = true;
        }       
    }while ($correctPrice == false);

?>

Answer 2

更正您的代码，为您提供do-while循环条件

    echo "<p> Lets hope I can get ray bans for under £30! </p>";
    $correctPrice = false;
    do {
        $rayBans = rand(0,70);
        if ($rayBans > 30) {
            echo "<p> raybans at $rayBans are too expensive </p>";
            $correctPrice = false;
        }
        else if ($rayBans < 30){
            echo "<p> Finaly got my rayBans for $rayBans </p>";
            $correctPrice = true;
        }


    }
    while ($correctPrice == false);

使用PHP do / while语句

2 个答案: