Why Am I Getting the 'Fatal error: Cannot redeclare ' Error in PHP?

Understanding the "Fatal error: Cannot redeclare " Error

The error "Fatal error: Cannot redeclare " indicates that a function with the specified name has already been defined in the script. This can occur in various scenarios:

• Multiple Functions with the Same Name: If you have multiple files containing functions with the same name, the interpreter will attempt to redeclare the function upon encountering the subsequent definition, resulting in the error.
• Redeclaration in the Same File: You can also encounter this error if you redeclare the same function within a single file, even if the declarations are separated by code.
• Repeated Inclusion of Function File: If you include a function file (e.g., "functions.php") multiple times, it may cause the interpreter to attempt to redeclare functions that are already defined within that file.

Possible Solutions

To resolve the error, you should identify the cause and take appropriate measures:

• Check for Multiple Function Definitions: Ensure that you do not have duplicate function definitions in different files or within the same file.
• Use include_once: To prevent repeated inclusion of function files, use the include_once directive instead of include. This ensures that the file is included only once, preventing function redeclaration.

In the case presented, the error occurs because the generate_salt() function is defined at the beginning of the file and then likely redeclared somewhere lower in the file. By checking the code and removing the duplicate definition, you can resolve the error.

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