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функция не описана

WP_Theme::get_core_default_theme() WP 4.4.0

Determines the latest WordPress default theme that is installed.

This hits the filesystem.

Это метод класса: WP_Theme

Хуков нет.

Возвращает

WP_Theme/false. Object, or false if no theme is installed, which would be bad.

Использование

$var = WP_Theme::get_core_default_theme();

Код WP Theme::get core default theme: wp-includes/class-wp-theme.php WP 5.2

<?php
public static function get_core_default_theme() {
	foreach ( array_reverse( self::$default_themes ) as $slug => $name ) {
		$theme = wp_get_theme( $slug );
		if ( $theme->exists() ) {
			return $theme;
		}
	}
	return false;
}