Table of Contents
回复讨论(解决方案)
Home Backend Development PHP Tutorial alert如何显示function方法返回的结果

alert如何显示function方法返回的结果

Jun 23, 2016 pm 02:02 PM

php;alert;function

如下代码:
function check($out) {
  $file_handle = fopen($out, 'r');
  while (!feof($file_handle)) {
    $line = fgets($file_handle);
    if (substr($line, 0, 6) == "#ERROR") {
      return substr($line, 8);
    }
  }
  fclose($file_handle);
  return "";
}

$out = "output/out.txt";
$error = check($out);
if ($error != "") {
  echo "<script>alert('$error');</script>";
  exit;
}
?>

此时无法弹出alert对话框。。。
但如果把check方法的return改为 return "abc",就能够弹出alert对话框了

我需要alert弹出的内容是从文件中获得的,请问如何修改?

回复讨论(解决方案)

$error在php打印是个什么东东看下不就知道了嘛

$error是从输出文件中捕获错误信息,然后通过对话框的形式显示给用户看

这段程序里能够正确获得$error的值,但是alert却无法弹出对话框

我这边帮你调试了是没问题的 可以正常弹出提示

我这边就是出不来……

function里的返回值是类似于substr吗?如果是直接返回字符串的话,是能够弹出来的

$error = check($out);
echo $error; 是什么结果

把你的out.txt发来看看
我的out.txt是这样的

把你的out.txt发来看看
我的out.txt是这样的


我似乎找到点原因了
如果文件只有一行或者最后一行是“#ERROR   abc”的话,能够正常弹出,但是如果后面还有别的信息,我的程序就不行了。。。

function check($out) {  $file_handle = fopen($out, 'r');  while (!feof($file_handle)) {    $line = fgets($file_handle);    if (substr($line, 0, 6) == "#ERROR") {      return preg_replace("/\s/","",substr($line, 8));//去掉换行    }  }  fclose($file_handle);}$out = "out.txt";$error = check($out);if ($error != "") {  echo "<script>alert(\"$error\");</script>";  exit;}
Copy after login

取出一行存在换行问题 把换行去掉就行了

我知道怎么改了,但是不知道为什么……

把所需要的字符串完全截出来就行了,比如“return substr($line, 8, 5)”,此时就能正常弹出了,是不是当不是最后一行时,substr会把一行末尾的换行符也取得,而alert无法处理……

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Explain JSON Web Tokens (JWT) and their use case in PHP APIs. Apr 05, 2025 am 12:04 AM

JWT is an open standard based on JSON, used to securely transmit information between parties, mainly for identity authentication and information exchange. 1. JWT consists of three parts: Header, Payload and Signature. 2. The working principle of JWT includes three steps: generating JWT, verifying JWT and parsing Payload. 3. When using JWT for authentication in PHP, JWT can be generated and verified, and user role and permission information can be included in advanced usage. 4. Common errors include signature verification failure, token expiration, and payload oversized. Debugging skills include using debugging tools and logging. 5. Performance optimization and best practices include using appropriate signature algorithms, setting validity periods reasonably,

How does session hijacking work and how can you mitigate it in PHP? How does session hijacking work and how can you mitigate it in PHP? Apr 06, 2025 am 12:02 AM

Session hijacking can be achieved through the following steps: 1. Obtain the session ID, 2. Use the session ID, 3. Keep the session active. The methods to prevent session hijacking in PHP include: 1. Use the session_regenerate_id() function to regenerate the session ID, 2. Store session data through the database, 3. Ensure that all session data is transmitted through HTTPS.

Describe the SOLID principles and how they apply to PHP development. Describe the SOLID principles and how they apply to PHP development. Apr 03, 2025 am 12:04 AM

The application of SOLID principle in PHP development includes: 1. Single responsibility principle (SRP): Each class is responsible for only one function. 2. Open and close principle (OCP): Changes are achieved through extension rather than modification. 3. Lisch's Substitution Principle (LSP): Subclasses can replace base classes without affecting program accuracy. 4. Interface isolation principle (ISP): Use fine-grained interfaces to avoid dependencies and unused methods. 5. Dependency inversion principle (DIP): High and low-level modules rely on abstraction and are implemented through dependency injection.

What are Enumerations (Enums) in PHP 8.1? What are Enumerations (Enums) in PHP 8.1? Apr 03, 2025 am 12:05 AM

The enumeration function in PHP8.1 enhances the clarity and type safety of the code by defining named constants. 1) Enumerations can be integers, strings or objects, improving code readability and type safety. 2) Enumeration is based on class and supports object-oriented features such as traversal and reflection. 3) Enumeration can be used for comparison and assignment to ensure type safety. 4) Enumeration supports adding methods to implement complex logic. 5) Strict type checking and error handling can avoid common errors. 6) Enumeration reduces magic value and improves maintainability, but pay attention to performance optimization.

How to debug CLI mode in PHPStorm? How to debug CLI mode in PHPStorm? Apr 01, 2025 pm 02:57 PM

How to debug CLI mode in PHPStorm? When developing with PHPStorm, sometimes we need to debug PHP in command line interface (CLI) mode...

How to automatically set permissions of unixsocket after system restart? How to automatically set permissions of unixsocket after system restart? Mar 31, 2025 pm 11:54 PM

How to automatically set the permissions of unixsocket after the system restarts. Every time the system restarts, we need to execute the following command to modify the permissions of unixsocket: sudo...

Explain late static binding in PHP (static::). Explain late static binding in PHP (static::). Apr 03, 2025 am 12:04 AM

Static binding (static::) implements late static binding (LSB) in PHP, allowing calling classes to be referenced in static contexts rather than defining classes. 1) The parsing process is performed at runtime, 2) Look up the call class in the inheritance relationship, 3) It may bring performance overhead.

See all articles