How can I get category ID by category name?

Question

I have a few categories with the same name [some of them are sub-categories]. And I want to get an array of ID's for certain cattegory name. I tried this:

 $term = get_term_by('name', $cat_name, 'category');

but it seems that get_term_by() returns only the first term that match the query.

Answer 1

Use get_terms(), which uses WP_Term_Query under the hood. For a full list of all the available parameters check out the documentation for WP_Term_Query::__construct

// Get term *IDs* with name that *matches* "my_name"
$term_ids = get_terms([
    'fields' => 'ids',
    'taxonomy' => 'category',
    'name' => 'my_name',
    'hide_empty' => false,
]);

// Get term *objects* with name that *matches* "my_name"
$terms = get_terms([
    'taxonomy' => 'category',
    'name' => 'my_name',
    'hide_empty' => false,
]);

// Get term *objects* with name that *contains* "my_name"
$terms = get_terms([
    'taxonomy' => 'category',
    'name__like' => 'my_name',
    'hide_empty' => false,
]);

Answer 2

get_cat_ID( $cat_name ) can do the trick! Example:

<?php
     $category_id = get_cat_ID('Category Name');
     $q = 'cat=' . $category_id;
     query_posts($q);
     if (have_posts()) : while (have_posts()) : the_post();

     the_content();

     endwhile; endif;
?>

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