最近项目使用到ThinkPHP框架，其中一个页面顶部总是一小段空白。
如下图所示：
而且只会在chrome和edge浏览器出现，ff则不会出现这个问题。由于该页面是由PHP+HTML模板拼接接，因此先后排查了html文件、JavaScript文件、php文件。均未发现问题。
使用chrome F12发现空白处是一串字符。通过搜索，了解到这原来是UTF-8的编码问题。
我使用的编码是UTF-8 + BOM，这种编码方式一般会在windows操作系统中出现，比如WINDOWS自带的记事本等软件，在保存一个以UTF-8编码的文件时，会在文件开始的地方插入三个不可见的字符（0xEF 0xBB 0xBF，即BOM）。它是一串隐藏的字符，用于让记事本等编辑器识别这个文件是否以UTF-8编码。对于一般的文件，这样并不会产生什么麻烦。但对于 PHP来说，BOM是个*烦。因为PHP并不会忽略BOM，所以在读取、包含或者引用这些文件时，会把BOM作为该文件开头正文的一部分。根据嵌入式语言的特点，这串字符将被直接执行（显示）出来。
知道问题的原因之后，便很好解决了。我使用的是 phpstorm，在菜单栏文件里有“remove bom”选项，可以直接存为UTF-8无BOM模式。如果使用notepad++或其他工具的也可以选择“另存为”，然后在编码那儿选择“UTF-8无BOM”即可解决。
The Continued Use of PHP: Reasons for Its EnduranceApr 19, 2025 am 12:23 AMWhat’s still popular is the ease of use, flexibility and a strong ecosystem. 1) Ease of use and simple syntax make it the first choice for beginners. 2) Closely integrated with web development, excellent interaction with HTTP requests and database. 3) The huge ecosystem provides a wealth of tools and libraries. 4) Active community and open source nature adapts them to new needs and technology trends.
PHP and Python: Exploring Their Similarities and DifferencesApr 19, 2025 am 12:21 AMPHP and Python are both high-level programming languages that are widely used in web development, data processing and automation tasks. 1.PHP is often used to build dynamic websites and content management systems, while Python is often used to build web frameworks and data science. 2.PHP uses echo to output content, Python uses print. 3. Both support object-oriented programming, but the syntax and keywords are different. 4. PHP supports weak type conversion, while Python is more stringent. 5. PHP performance optimization includes using OPcache and asynchronous programming, while Python uses cProfile and asynchronous programming.
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PHP and Python: A Deep Dive into Their HistoryApr 18, 2025 am 12:25 AMPHP originated in 1994 and was developed by RasmusLerdorf. It was originally used to track website visitors and gradually evolved into a server-side scripting language and was widely used in web development. Python was developed by Guidovan Rossum in the late 1980s and was first released in 1991. It emphasizes code readability and simplicity, and is suitable for scientific computing, data analysis and other fields.
Choosing Between PHP and Python: A GuideApr 18, 2025 am 12:24 AMPHP is suitable for web development and rapid prototyping, and Python is suitable for data science and machine learning. 1.PHP is used for dynamic web development, with simple syntax and suitable for rapid development. 2. Python has concise syntax, is suitable for multiple fields, and has a strong library ecosystem.
PHP and Frameworks: Modernizing the LanguageApr 18, 2025 am 12:14 AMPHP remains important in the modernization process because it supports a large number of websites and applications and adapts to development needs through frameworks. 1.PHP7 improves performance and introduces new features. 2. Modern frameworks such as Laravel, Symfony and CodeIgniter simplify development and improve code quality. 3. Performance optimization and best practices further improve application efficiency.
PHP's Impact: Web Development and BeyondApr 18, 2025 am 12:10 AMPHPhassignificantlyimpactedwebdevelopmentandextendsbeyondit.1)ItpowersmajorplatformslikeWordPressandexcelsindatabaseinteractions.2)PHP'sadaptabilityallowsittoscaleforlargeapplicationsusingframeworkslikeLaravel.3)Beyondweb,PHPisusedincommand-linescrip
How does PHP type hinting work, including scalar types, return types, union types, and nullable types?Apr 17, 2025 am 12:25 AMPHP type prompts to improve code quality and readability. 1) Scalar type tips: Since PHP7.0, basic data types are allowed to be specified in function parameters, such as int, float, etc. 2) Return type prompt: Ensure the consistency of the function return value type. 3) Union type prompt: Since PHP8.0, multiple types are allowed to be specified in function parameters or return values. 4) Nullable type prompt: Allows to include null values and handle functions that may return null values.
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