Source

File: wp-includes/option.php

function delete_option( $option ) {
	global $wpdb;

	$option = trim( $option );
	if ( empty( $option ) ) {
		return false;
	}

	wp_protect_special_option( $option );

	// Get the ID, if no ID then return.
	$row = $wpdb->get_row( $wpdb->prepare( "SELECT autoload FROM $wpdb->options WHERE option_name = %s", $option ) );
	if ( is_null( $row ) ) {
		return false;
	}

	/**
	 * Fires immediately before an option is deleted.
	 *
	 * @since 2.9.0
	 *
	 * @param string $option Name of the option to delete.
	 */
	do_action( 'delete_option', $option );

	$result = $wpdb->delete( $wpdb->options, array( 'option_name' => $option ) );

	if ( ! wp_installing() ) {
		if ( 'yes' === $row->autoload ) {
			$alloptions = wp_load_alloptions( true );
			if ( is_array( $alloptions ) && isset( $alloptions[ $option ] ) ) {
				unset( $alloptions[ $option ] );
				wp_cache_set( 'alloptions', $alloptions, 'options' );
			}
		} else {
			wp_cache_delete( $option, 'options' );
		}
	}

	if ( $result ) {

		/**
		 * Fires after a specific option has been deleted.
		 *
		 * The dynamic portion of the hook name, `$option`, refers to the option name.
		 *
		 * @since 3.0.0
		 *
		 * @param string $option Name of the deleted option.
		 */
		do_action( "delete_option_{$option}", $option );

		/**
		 * Fires after an option has been deleted.
		 *
		 * @since 2.9.0
		 *
		 * @param string $option Name of the deleted option.
		 */
		do_action( 'deleted_option', $option );

		return true;
	}

	return false;
}