Question

所以我在编写HTML CSS和PHP时相当新，现在我正在关注PHP。我们的教授要求我们在我们的网站（没有数据库）中加入PHP代码，并尝试使用for循环和echo打印一个数组。

问题是回声没有显示在网页上，我现在丢失了

下面是我的代码：

<html>
<head>
<title>PHP Loops and Sorts</title>
<body>
<h1>PHP Loops and Sorts</h1>

<div class="container">
<?php
$dogs=Array("Labrador Retriever","German Shepherd","Bulldog","Golden Retriever","Poodle","Beagle","Rottweiler","Yorkshire Terrier","Siberian Husky","Dachshund","Chihuahua","Pug","Great Dane","Dobermann","Shih Tzu");
$cats=Array("Persian","Siamese","Maine Coon","Ragdoll","Sphynx","British Shorthair","Abyssinian","Bengal","Scottish Fold","Himalayan","Russian Blue","Siberian","Munchkin");
$birds=Array("Canaries","Budgies","Finches","Cockatiels","Quaker Parakeets","Pionus Parrots","Poicephalus Parrots","Amazon Parrots","Pyrrhura Conures","Peach-Faced Lovebirds");
$fishes=Array("Koi","Fantail","Oranda","Comet","Black Telescope","Butterfly Tail","Ryukin","Goldfish","Lionhead","Mirror Carp");

function countsize($array,$size){
    $size = count($array);
    return $size;
}

if(isset($_POST['btnShow']) )
    {
        $arraypick=$_POST['formAnimal'];
        $arrsize = countsize($arraypick,$size);
        for(&x = 0,$x<$arrsize,$x++){
            echo $arraypick[$x] . "<br>";
        }
    }
?>
Breeds of different kinds of animals. Select what animal's breed to be shown:<br>
    <select name="formAnimal">
  <option value="">Choose animal</option>
  <option value="dogs">Dog</option>
  <option value="cats">Cat</option>
  <option value="birds">Bird</option>
  <option value="fishes">Fish</option>
</select><br><br>
<div style="margin:auto,text-align:center;text-align:center">
<INPUT TYPE = "Submit" Name = "btnShow" VALUE = "Show List">&emsp;
<INPUT TYPE = "Submit" Name = "btnAsc" VALUE = "Show Ascending">&emsp;
<INPUT TYPE = "Submit" Name = "btnDes" VALUE = "Show Descending">
</div>


<?php

echo $size

?>

</div>
</body>
</html>

Answer 1

您需要在身体标签前关闭头部标签。

您也不需要将大小传递给方法计数大小。

function countsize (&array) {
    return count(&array);
}

Answer 2

for循环的语法不正确。查看php documentation

此外，$size变量永远不会在您使用它的范围内声明。

Answer 3

没有得到你如何使用$ arrsize但你在初始化循环时使用＆amp; x而不是$ x。

#include <fstream>  // for std::ifstream
#include <string>   // for std::string
#include <cstring>  // for strcpy()

std::ifstream infile("garbage.txt");
if (infile.is_open())
{
    int age;
    std::string namestr;
    while (infile >> age >> namestr)
    {
        stud1 temp;
        temp.age = age;
        strcpy( temp.name, namestr.c_str() );
        // do whatever before struct goes out of scope
    }
    infile.close();
}

Answer 4

更改以下代码行：

$dogs=Array("Labrador Retriever","German Shepherd","Bulldog","Golden Retriever","Poodle","Beagle","Rottweiler","Yorkshire Terrier","Siberian Husky","Dachshund","Chihuahua","Pug","Great Dane","Dobermann","Shih Tzu");
$cats=Array("Persian","Siamese","Maine Coon","Ragdoll","Sphynx","British Shorthair","Abyssinian","Bengal","Scottish Fold","Himalayan","Russian Blue","Siberian","Munchkin");
$birds=Array("Canaries","Budgies","Finches","Cockatiels","Quaker Parakeets","Pionus Parrots","Poicephalus Parrots","Amazon Parrots","Pyrrhura Conures","Peach-Faced Lovebirds");
$fishes=Array("Koi","Fantail","Oranda","Comet","Black Telescope","Butterfly Tail","Ryukin","Goldfish","Lionhead","Mirror Carp");

function countsize($array,$size){
$size = count($array);
return $size;

}

$arraypick=$_POST['formAnimal'];
    $arrsize = countsize($arraypick,$size);
    for(&x = 0,$x<$arrsize,$x++){
        echo $arraypick[$x] . "<br>";
    }

致：

$animalArray['dogs']=Array("Labrador Retriever","German Shepherd","Bulldog","Golden Retriever","Poodle","Beagle","Rottweiler","Yorkshire Terrier","Siberian Husky","Dachshund","Chihuahua","Pug","Great Dane","Dobermann","Shih Tzu");
$animalArray['cats']=Array("Persian","Siamese","Maine Coon","Ragdoll","Sphynx","British Shorthair","Abyssinian","Bengal","Scottish Fold","Himalayan","Russian Blue","Siberian","Munchkin");
$animalArray['birds']=Array("Canaries","Budgies","Finches","Cockatiels","Quaker Parakeets","Pionus Parrots","Poicephalus Parrots","Amazon Parrots","Pyrrhura Conures","Peach-Faced Lovebirds");
$animalArray['fishes']=Array("Koi","Fantail","Oranda","Comet","Black Telescope","Butterfly Tail","Ryukin","Goldfish","Lionhead","Mirror Carp");

 function countsize($index){
  return count($animalArray[$index]);
}
    $arraypick=$_POST['formAnimal'];
    $arrsize = countsize($arraypick);
    for($x = 0;$x<$arrsize;$x++){
        echo $animalArray[$arraypick][$x] . "<br>";
    }

Answer 5

if(isset($_POST['btnShow']) )你确定它已经确定了吗？

根据我们的代码，你甚至不能POST，你错过了form标签

尝试用以下内容包装输入：

<form method="POST">
    <!--inputs-->
</form>

PHP echo不会显示在网页中

5 个答案: