What does the '@' before php @file_exists mean?

php @file_exists What does the "@" in front mean? The following article will help you understand the function of the "@" symbol.

The role of the @ symbol in PHP

In PHP, the @ symbol is an error control symbol used to suppress the output of error messages.

The following is a brief introduction to the error control symbols in PHP:

In PHP, if an error occurs in a certain statement, the system will automatically output error information, including the type of error and the time when the error occurred. File and the specific number of lines where the error occurred, etc. This is very beneficial for locating problems and debugging, allowing you to quickly find the error and resolve it.

However, in some cases, outputting error messages will affect the program itself and may cause the program to fail to run normally. For example, in some operations that affect user experience, the occurrence of error messages will affect the user experience. At this point, we hope to not output an error message when the program makes an error, but to be able to handle the error ourselves. At this time, the error control symbol @ comes in handy.

In PHP, if an error occurs when a statement with the @ symbol is executed, the error message will be shielded and no error message will be output to avoid affecting the normal operation of the program.

The following uses examples to further illustrate the role of the @ symbol.

Example description

In PHP, if we want to determine whether a file exists, we can use the file_exists function. This function checks whether a file or directory exists and returns true if it exists, otherwise it returns false.

For example, we can use the following statement to determine whether a file exists:

if (file_exists("/path/to/file")) { echo "文件存在"; } else { echo "文件不存在"; }

The above statement will output whether the file exists or the file does not exist, depending on whether the determined file exists.

However, if we change the above statement to the following:

if (@file_exists("/path/to/file")) { echo "文件存在"; } else { echo "文件不存在"; }

After adding the "@" symbol, no error message will be output when determining whether the file exists.

It should be noted that adding the @ symbol when the program is running will block all error messages, so it may cause some hidden errors, making it more difficult to find and locate problems. Therefore, use the @ symbol with caution and only when necessary.

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