The role of php function header
The role of the php function header
The function of the header() function in PHP is to send header information to the client .
Recommended: [PHP Tutorial]
What is header information?
Here is only a brief explanation, please read the http protocol in detail.
In the HTTP protocol, the server-side response content includes two parts: header information (header) and body content. The header information here is not the
part in HTML. Likewise, body content is not < /BODY>. The header information is invisible to the user and contains many items, including server information, date, content length, etc. The body content is the entire HTML, which is everything you can see.What is the use of header information?
Header information has many functions, the most important of which are the following:
1. Jump: When the browser receives the Location: xxxx in the header information, it will automatically Jump to the URL address pointed to by xxxx. This is somewhat similar to using js to write a jump. But this jump is only known by the browser, and users cannot see it regardless of whether there is anything in the content.
2. Specify the content of the web page: For the same XML file, if the header information specifies: Content-type: application/xml, the browser will parse it according to the XML file format. However, if the header information is: Content-type: text/xml, the browser will parse it as stored text. (Browsers do not parse files based on extensions)
3. Attachment: I don’t know if you have noticed that sometimes when you download something from some websites and click the download link, the browser opens the attachment as a web page. , all displayed are garbled characters, this problem is also related to the header information. Sometimes the browser determines whether to open or save based on Content-type, so sometimes it will make a wrong judgment (mainly because the website designer forgets to write Content-type). In fact, there is another way to specify that the content is an attachment and needs to be saved. This is: Content-Disposition: attachment; filename="xxxxx"
How to write it in PHP?
1. Jump:
header("Location: http://www.example.com/");2. Specified content:
header('Content-type: application/pdf');
3. Attachment:
// 指定内容为附件 header('Content-Disposition: attachment; filename="downloaded.pdf"'); // 打开文件，并输出 readfile('original.pdf');
Finally, I would like to remind everyone to pay attention to something , all header information must precede the body content. If there is any output, the header information written by the header function will be useless. For example, at the beginning of the file
The above is the detailed content of The role of php function header. For more information, please follow other related articles on the PHP Chinese website!
Hot AI Tools
Undresser.AI Undress
AI-powered app for creating realistic nude photos
AI Clothes Remover
Online AI tool for removing clothes from photos.
Undress AI Tool
Undress images for free
Clothoff.io
AI clothes remover
Video Face Swap
Swap faces in any video effortlessly with our completely free AI face swap tool!
Hot Article
Hot Tools
Notepad++7.3.1
Easy-to-use and free code editor
SublimeText3 Chinese version
Chinese version, very easy to use
Zend Studio 13.0.1
Powerful PHP integrated development environment
Dreamweaver CS6
Visual web development tools
SublimeText3 Mac version
God-level code editing software (SublimeText3)
Hot Topics
1666
14
1426
52
1328
25
1273
29
1255
24
PHP: A Key Language for Web Development
Apr 13, 2025 am 12:08 AM
PHP is a scripting language widely used on the server side, especially suitable for web development. 1.PHP can embed HTML, process HTTP requests and responses, and supports a variety of databases. 2.PHP is used to generate dynamic web content, process form data, access databases, etc., with strong community support and open source resources. 3. PHP is an interpreted language, and the execution process includes lexical analysis, grammatical analysis, compilation and execution. 4.PHP can be combined with MySQL for advanced applications such as user registration systems. 5. When debugging PHP, you can use functions such as error_reporting() and var_dump(). 6. Optimize PHP code to use caching mechanisms, optimize database queries and use built-in functions. 7
PHP and Python: Comparing Two Popular Programming Languages
Apr 14, 2025 am 12:13 AM
PHP and Python each have their own advantages, and choose according to project requirements. 1.PHP is suitable for web development, especially for rapid development and maintenance of websites. 2. Python is suitable for data science, machine learning and artificial intelligence, with concise syntax and suitable for beginners.
PHP vs. Python: Understanding the Differences
Apr 11, 2025 am 12:15 AM
PHP and Python each have their own advantages, and the choice should be based on project requirements. 1.PHP is suitable for web development, with simple syntax and high execution efficiency. 2. Python is suitable for data science and machine learning, with concise syntax and rich libraries.
PHP in Action: Real-World Examples and Applications
Apr 14, 2025 am 12:19 AM
PHP is widely used in e-commerce, content management systems and API development. 1) E-commerce: used for shopping cart function and payment processing. 2) Content management system: used for dynamic content generation and user management. 3) API development: used for RESTful API development and API security. Through performance optimization and best practices, the efficiency and maintainability of PHP applications are improved.
The Enduring Relevance of PHP: Is It Still Alive?
Apr 14, 2025 am 12:12 AM
PHP is still dynamic and still occupies an important position in the field of modern programming. 1) PHP's simplicity and powerful community support make it widely used in web development; 2) Its flexibility and stability make it outstanding in handling web forms, database operations and file processing; 3) PHP is constantly evolving and optimizing, suitable for beginners and experienced developers.
PHP vs. Other Languages: A Comparison
Apr 13, 2025 am 12:19 AM
PHP is suitable for web development, especially in rapid development and processing dynamic content, but is not good at data science and enterprise-level applications. Compared with Python, PHP has more advantages in web development, but is not as good as Python in the field of data science; compared with Java, PHP performs worse in enterprise-level applications, but is more flexible in web development; compared with JavaScript, PHP is more concise in back-end development, but is not as good as JavaScript in front-end development.
PHP and Python: Different Paradigms Explained
Apr 18, 2025 am 12:26 AM
PHP is mainly procedural programming, but also supports object-oriented programming (OOP); Python supports a variety of paradigms, including OOP, functional and procedural programming. PHP is suitable for web development, and Python is suitable for a variety of applications such as data analysis and machine learning.
PHP and Python: Code Examples and Comparison
Apr 15, 2025 am 12:07 AM
PHP and Python have their own advantages and disadvantages, and the choice depends on project needs and personal preferences. 1.PHP is suitable for rapid development and maintenance of large-scale web applications. 2. Python dominates the field of data science and machine learning.
