Source

File: wp-includes/l10n.php

function _nx( $single, $plural, $number, $context, $domain = 'default' ) {
	$translations = get_translations_for_domain( $domain );
	$translation  = $translations->translate_plural( $single, $plural, $number, $context );

	/**
	 * Filters the singular or plural form of a string with gettext context.
	 *
	 * @since 2.8.0
	 *
	 * @param string $translation Translated text.
	 * @param string $single      The text to be used if the number is singular.
	 * @param string $plural      The text to be used if the number is plural.
	 * @param string $number      The number to compare against to use either the singular or plural form.
	 * @param string $context     Context information for the translators.
	 * @param string $domain      Text domain. Unique identifier for retrieving translated strings.
	 */
	$translation = apply_filters( 'ngettext_with_context', $translation, $single, $plural, $number, $context, $domain );

	/**
	 * Filters the singular or plural form of a string with gettext context for a domain.
	 *
	 * The dynamic portion of the hook, `$domain`, refers to the text domain.
	 *
	 * @since 5.5.0
	 *
	 * @param string $translation Translated text.
	 * @param string $single      The text to be used if the number is singular.
	 * @param string $plural      The text to be used if the number is plural.
	 * @param string $number      The number to compare against to use either the singular or plural form.
	 * @param string $context     Context information for the translators.
	 * @param string $domain      Text domain. Unique identifier for retrieving translated strings.
	 */
	$translation = apply_filters( "ngettext_with_context_{$domain}", $translation, $single, $plural, $number, $context, $domain );

	return $translation;
}