the_category_ID() │ WP 0.71

Deprecated since 0.7. It is no longer supported and may be removed in future releases. Use get_the_category() instead.

Returns or prints a category ID.

No Hooks.

Returns

Int. Category ID.

Usage

the_category_ID( $display );
$display(true|false)
Whether to display the output.
Default: true

Notes

Changelog

Since 0.71 Introduced.
Deprecated since 0.71 Use get_the_category()

the_category_ID() code WP 6.9

wp-includes/deprecated.php 
function the_category_ID($display = true) {
	_deprecated_function( __FUNCTION__, '0.71', 'get_the_category()' );

	// Grab the first cat in the list.
	$categories = get_the_category();
	$cat = $categories[0]->term_id;

	if ( $display )
		echo $cat;

	return $cat;
}