$arrays that are NOT arrays.
	foreach ( $arrays as $key => $array ) {
		if ( ! is_array( $array ) ) {
			unset( $arrays[ $key ] );
		}
	}

	// We start by setting the first array as our final array.
	// We will merge all other arrays with this one.
	$final = array_shift( $arrays );

	foreach ( $arrays as $b ) {
		foreach ( $final as $key => $value ) {
			// If $key does not exist in $b, then it is unique and can be safely merged.
			if ( ! isset( $b[ $key ] ) ) {
				$final[ $key ] = $value;
			} else {
				// If $key is present in $b, then we need to merge and sum numeric values in both.
				if ( is_numeric( $value ) && is_numeric( $b[ $key ] ) ) {
					// If both values for these keys are numeric, we sum them.
					$final[ $key ] = $value + $b[ $key ];
				} elseif ( is_array( $value ) && is_array( $b[ $key ] ) ) {
					// If both values are arrays, we recursively call ourself.
					$final[ $key ] = wc_array_merge_recursive_numeric( $value, $b[ $key ] );
				} else {
					// If both keys exist but differ in type, then we cannot merge them.
					// In this scenario, we will $b's value for $key is used.
					$final[ $key ] = $b[ $key ];
				}
			}
		}

		// Finally, we need to merge any keys that exist only in $b.
		foreach ( $b as $key => $value ) {
			if ( ! isset( $final[ $key ] ) ) {
				$final[ $key ] = $value;
			}
		}
	}

	return $final;
}

/**
 * Implode and escape HTML attributes for output.
 *
 * @since 3.3.0
 * @param array $raw_attributes Attribute name value pairs.
 * @return string
 */
function wc_implode_html_attributes( $raw_attributes ) {
	$attributes = array();
	foreach ( $raw_attributes as $name => $value ) {
		$attributes[] = esc_attr( $name ) . '="' . esc_attr( $value ) . '"';
	}
	return implode( ' ', $attributes );
}

/**
 * Escape JSON for use on HTML or attribute text nodes.
 *
 * @since 3.5.5
 * @param string $json JSON to escape.
 * @param bool   $html True if escaping for HTML text node, false for attributes. Determines how quotes are handled.
 * @return string Escaped JSON.
 */
function wc_esc_json( $json, $html = false ) {
	return _wp_specialchars(
		$json,
		$html ? ENT_NOQUOTES : ENT_QUOTES, // Escape quotes in attribute nodes only.
		'UTF-8',                           // json_encode() outputs UTF-8 (really just ASCII), not the blog's charset.
		true                               // Double escape entities: `&` -> `&`.
	);
}

/**
 * Parse a relative date option from the settings API into a standard format.
 *
 * @since 3.4.0
 * @param mixed $raw_value Value stored in DB.
 * @return array Nicely formatted array with number and unit values.
 */
function wc_parse_relative_date_option( $raw_value ) {
	$periods = array(
		'days'   => __( 'Day(s)', 'woocommerce' ),
		'weeks'  => __( 'Week(s)', 'woocommerce' ),
		'months' => __( 'Month(s)', 'woocommerce' ),
		'years'  => __( 'Year(s)', 'woocommerce' ),
	);

	$value = wp_parse_args(
		(array) $raw_value,
		array(
			'number' => '',
			'unit'   => 'days',
		)
	);

	$value['number'] = ! empty( $value['number'] ) ? absint( $value['number'] ) : '';

	if ( ! in_array( $value['unit'], array_keys( $periods ), true ) ) {
		$value['unit'] = 'days';
	}

	return $value;
}

/**
 * Format the endpoint slug, strip out anything not allowed in a url.
 *
 * @since 3.5.0
 * @param string $raw_value The raw value.
 * @return string
 */
function wc_sanitize_endpoint_slug( $raw_value ) {
	return sanitize_title( $raw_value ?? '' );
}

/**
 * Removes useless non-displayable and problematic Unicode characters from a string.
 *
 * Covers the characters that are invisible to the reader but still count as content to
 * anything matching on the string: soft hyphen, zero-width spaces and joiners, bidirectional
 * marks, isolates and overrides, variation selectors, Hangul and Mongolian fillers, tag
 * characters, and the byte order mark. Interlinear annotation marks (`U+FFF9`–`U+FFFB`) are
 * removed too, though they are not invisible.
 *
 * Copy-pasting from PDFs, word processors and web pages routinely carries these along, and a
 * reader has no way to see why the value they pasted is being rejected.
 *
 * Non-breaking spaces (`U+00A0`, `U+202F`) are **not** removed. They are visible spaces, so
 * deleting them would run words together rather than restore the intended text.
 *
 * @param string $raw_value The input string to sanitize.
 *
 * @return string The sanitized string without problematic characters.
 * @since 9.9.0
 * @since 11.2.0 Removes every Unicode default-ignorable code point, including the word joiner
 *               (`U+2060`) and the variation selectors earlier versions kept.
 */
function wc_remove_non_displayable_chars( string $raw_value ): string {
	// Ranges rather than \p{Default_Ignorable_Code_Point}: that property needs PCRE2 10.43,
	// newer than the build many supported installs link against. An unsupported property
	// makes preg_replace return null instead of failing loudly.
	$pattern = '/['
		. '\x{00AD}\x{034F}\x{061C}\x{115F}\x{1160}\x{17B4}\x{17B5}\x{180B}-\x{180F}'
		. '\x{200B}-\x{200F}\x{202A}-\x{202E}\x{2060}-\x{206F}\x{3164}'
		. '\x{FE00}-\x{FE0F}\x{FEFF}\x{FFA0}\x{FFF0}-\x{FFFB}'
		. '\x{1BCA0}-\x{1BCA3}\x{1D173}-\x{1D17A}\x{E0000}-\x{E0FFF}'
		. ']/u';

	$result = preg_replace( $pattern, '', $raw_value );

	if ( null !== $result ) {
		return $result;
	}

	// Malformed UTF-8 makes a /u pattern bail. Fall back to a byte-wise replacement over the
	// soft hyphen, zero-width characters, bidirectional marks, BOM and interlinear annotation
	// marks, so such input is cleaned no less than it was before this pattern existed.
	$fallback_chars = array(
		"\u{00AD}",
		"\u{200B}",
		"\u{200C}",
		"\u{200D}",
		"\u{200E}",
		"\u{200F}",
		"\u{202A}",
		"\u{202B}",
		"\u{202C}",
		"\u{202D}",
		"\u{202E}",
		"\u{FEFF}",
		"\u{FFF9}",
		"\u{FFFA}",
		"\u{FFFB}",
	);

	return str_replace( $fallback_chars, '', $raw_value );
}

add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_checkout_pay_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_checkout_order_received_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_add_payment_method_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_delete_payment_method_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_set_default_payment_method_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_orders_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_view_order_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_order_withdrawal_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_stock_notifications_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_downloads_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_edit_account_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_edit_address_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_payment_methods_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_myaccount_lost_password_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );
add_filter( 'woocommerce_admin_settings_sanitize_option_woocommerce_logout_endpoint', 'wc_sanitize_endpoint_slug', 10, 1 );