我有一些帖子，只有当它们是给定父类别的子类别时，我才想在帖子内容后回显这些类别。

示例：

父类别：目标；目标：品牌意识、品牌参与度

如果一篇文章被分类，我希望它呼应出这些类别：

<?php
    $categories = get_the_category();
    $seperator = \' \';
    $output = \'\';
    if($categories)
    {
        foreach($categories as $category) 
        {
            $output .= \'<a href="\'.get_category_link($category->term_id ).\'" title="\' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . \'">\'.$category->cat_name.\'</a>\'.$seperator;
        }
        echo trim($output, $seperator);
    }
?>

我正在使用它，但它显然输出所有类别，而不仅仅是；“目标”；鼻涕虫

编辑：当前设置看起来像这样，但似乎不起作用。如果我用身份证，没关系：

<?php
        $categories = get_the_category();
        $seperator = \', \';
        $output = \'<strong>GOAL:</strong> \';
        $category = get_category_by_slug(\'goal\');
        if($categories)
        {
            foreach( $categories as $category ) 
            {
            if ( $category->parent == $category->term_id )
                $output .= \'<a href="\'.get_category_link($category->term_id ).\'" title="\' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . \'">\'.$category->cat_name.\'</a>\'.$seperator;
        }
        echo trim($output, $seperator);
}
?>

$goal = get_category_by_slug(\'goal\');
foreach($categories as $category) 
{
    $output .= \'<a href="\'.get_category_link($category->term_id ).\'" title="\' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . \'">\'.$category->cat_name.\'</a>\'.$seperator;
}

foreach( $categories as $category ) {
    if ( $category->parent == $goal->term_id)
        $output .= \'<a href="\'.get_category_link($category->term_id ).\'" title="\' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . \'">\'.$category->cat_name.\'</a>\'.$seperator;
}

<?php
    $goal_id = get_category_by_slug(\'goal\');

    $categories = get_the_category();
    $seperator = \' \';
    $output = \'\';
    if($categories)
    {
        foreach($categories as $category) 
        {
            if($category->parent == $goal->term_id){
                $output .= \'<a href="\'.get_category_link($category->term_id ).\'" title="\' . esc_attr( sprintf( __( "View all posts in %s" ), $category->name ) ) . \'">\'.$category->cat_name.\'</a>\'.$seperator;
            }
        }
        echo trim($output, $seperator);
    }
?>

//To show child  of cat with id - 4
if($category->category_parent == \'4\') 
    $output .= \'foo\';