Function and usage of is_serialized() in wordpress


Answers ( 1 )


    The is_serialized() function in WordPress is used to check if a given value, typically a string, is in a serialized format. Serialization is a process of converting a data structure or object state into a format that can be stored or transmitted and reconstructed later. In WordPress, serialized data is often used to store array or object data in the database.

    Here's a detailed explanation of is_serialized():

    Function Signature

    is_serialized( string $data, bool $strict = true ): bool


    • Purpose: To check whether a given value was serialized.


    • The function primarily checks if the provided $data is in a serialized format.
    • Serialized data is always a string, representing complex data types (like arrays or objects) in a storable format.
    • If $data is not a string, is_serialized() will always return false, since serialization implies string representation.


    1. $data (string, required): The value that needs to be checked for serialization. It's expected to be a string.
    2. $strict (bool, optional): Determines how strictly the function checks the end of the string for proper serialization format.
      • Default: true. When set to true, the function strictly checks for a proper serialized string format, including the ending characters.


    • bool: The function returns true if $data is serialized, and false if it is not.

    Sample Usage:

    Here's an example of how you might use is_serialized():

    $maybe_serialized = 'a:1:{s:3:"foo";s:3:"bar";}';
    $is_serialized = is_serialized($maybe_serialized);
    // $is_serialized is true since $maybe_serialized is a serialized string
    $not_serialized = 'Hello, world!';
    $is_not_serialized = is_serialized($not_serialized);
    // $is_not_serialized is false since $not_serialized is not a serialized string

    In this example, the function is used to check if a string is serialized. The first string ($maybe_serialized) is a serialized array, so is_serialized() returns true. The second string ($not_serialized) is a regular string and not in a serialized format, so is_serialized() returns false.

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