WordPress函数get_cat_ID()通过分类名获取分类ID

描述：

通过分类名获取分类ID

用法：

<?php get_cat_ID( $cat_name ) ?>

 参数：

$cat_name

(string) (可选) 默认值为“General”，可以是任何类别名称。

默认值: ‘General’

示例：

<?php
$category_id = get_cat_ID('Category Name');
 <!-- Start the Loop. -->
 <?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

 <!-- Test if the current post is in category "Category Name". -->
 <!-- If it is, the div box is given the CSS class "post-cat-special". -->
 <!-- Otherwise, the div box is given the CSS class "post". -->

 <?php if ( in_category($category_id) ) { ?>
           <div class="post-cat-special">
 <?php } else { ?>
           <div class="post">
 <?php } ?>
</div>
 <!-- Stop The Loop (but note the "else:" - see next line). -->

 <?php endwhile; else: ?>


 <!-- The very first "if" tested to see if there were any Posts to -->
 <!-- display.  This "else" part tells what do if there weren't any. -->
 <p>Sorry, no posts matched your criteria.</p>


 <!-- REALLY stop The Loop. -->
 <?php endif; ?>

源文件：

/**
 * Retrieve the ID of a category from its name.
 *
 * @since 1.0.0
 *
 * @param string $cat_name Category name.
 * @return int 0, if failure and ID of category on success.
 */
function get_cat_ID( $cat_name ) {
	$cat = get_term_by( 'name', $cat_name, 'category' );
	if ( $cat )
		return $cat->term_id;
	return 0;
}