How to sanitize boolean values for REST API in WordPress

The rest_sanitize_boolean function in WordPress is a sanitization function specifically designed to handle boolean values. It is used to sanitize input data, ensuring that it is a boolean before it is used or stored in the database.

Sanitization is a critical aspect of web development, particularly when dealing with user input data. The rest_sanitize_boolean function contributes to this process by ensuring that the data being handled is indeed a boolean value, which can help prevent errors or unexpected behavior in the code.

The function works by converting a variety of truthy and falsy values into their respective boolean counterparts. For instance, it will convert the string ‘true’ into the boolean value true, and ‘false’ into false. This is particularly useful when dealing with data that may come from different sources or formats, as it ensures consistency in the type of data being handled.

Parameters Accepted by the rest_sanitize_boolean Function

The rest_sanitize_boolean function in WordPress accepts a single parameter, as described below:

  • $value (bool|string|int), required: This is the value that is to be evaluated by the function.

Return Value of the rest_sanitize_boolean Function

The rest_sanitize_boolean function returns a boolean value. Specifically, it returns the appropriate boolean representation of the input value.


How to sanitize a boolean value

The rest_sanitize_boolean function is commonly used to sanitize boolean values. This function takes in a value and returns a boolean equivalent of the value. It’s useful when you want to ensure that the value you’re working with is a boolean.

$value = 'true';
$sanitized_value = rest_sanitize_boolean( $value );

How to use rest_sanitize_boolean in a conditional statement

In this example, the rest_sanitize_boolean function is used in a conditional statement. If the sanitized value of $value is true, it will echo “The value is true”.

$value = 'true';
if ( rest_sanitize_boolean( $value ) ) {
 echo 'The value is true';
} else {
 echo 'The value is false';

How to use rest_sanitize_boolean in a loop

The rest_sanitize_boolean function can also be used in a loop. In this example, an array of values is looped through and each value is sanitized using the rest_sanitize_boolean function. The sanitized values are then stored in the $sanitized_values array.

$values = array( 'true', 'false', '1', '0', 'yes', 'no' );
$sanitized_values = array();

foreach ( $values as $value ) {
 $sanitized_values[] = rest_sanitize_boolean( $value );


The rest_sanitize_boolean function in WordPress is a utility function that helps in sanitizing boolean input in REST API requests. The function ensures that the boolean values are correctly interpreted, regardless of how they are represented in the request, be it as a string, integer, or boolean. This is particularly useful when handling REST API requests where the data type of the request parameters might not be strictly controlled. By using rest_sanitize_boolean, developers can ensure consistent and reliable processing of boolean data in their REST API implementations.

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