If is category id not working

I think u need to use an if statement over there ,
is_category() is returning true or false , but it is not used .

I used this to exclude a single category “test category one”from appearing below the post:

<?php
// For each of the categories, create them as category variables
foreach((get_the_category()) as $category) {
    // If the category is NOT the cat_name (category name) then echo some stuff
    // So grab all... except where they match cat_name (exclude basically)
    if ($category->cat_name != 'Test Category One') {
    echo '<a href="' . get_category_link( $category->term_id ) . '" title="' . sprintf( __( "View all posts in %s" ), $category->name ) . '" ' . '>' . $category->name.'</a> ';
}
}
?>

but you’d have to mod it to exclude more than one. I haven’t been successful yet.

Thanks a lot.
I just tried this and broke my page

<?php if (is_category( array( '3,7,18,28' ) )); ?>
<?php $category = get_the_category();
		if($category[0]){
		echo '<a href="'.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'</a>';
		}
	?><?php endif ;?>

also I tried this but again the category link is displayed for all categories

<?php if (is_category( array( '3,7,18,28' ) )); ?>
<?php $category = get_the_category();
		if($category[0]){
		echo '<a href="'.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'</a>';
		}
	?><?php ;?>

I think I’m doing something wrong…

Maybe something in my file that doesn’t make it work. here it’s all the final part of the category.php template https://pastebin.com/FwePp8nN

the if statement shouldn’t be followed by a semi-column .
U can try using this snippet :

<?php if (is_category( array( '3,7,18,28' ) ))
                {$category = get_the_category();
		if($category[0]){
		echo '<a href="'.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'</a>';
                    }
                }
	?>

<?php is_category( array( 3,7,18,28 ) ); ?>

Thanks for your help!

ahmedNaguib it doesn’t display link for any category.

alchymyth I used this but shows link for all categories

<?php is_category( array( 3,7,18,28 ) ); ?>
<?php
		$category = get_the_category();
		if($category[0]){
		echo '<a href="'.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'</a>';
		}
	?><?php ;?>

sorry , I wrote a wrong array of categories , try it now:

<?php if (is_category( array( 3,7,18,28 ) ))
                {$category = get_the_category();
		if($category[0]){
		echo '<a href="'.get_category_link($category[0]->term_id ).'">'.$category[0]->cat_name.'</a>';
                    }
                }
	?>

AWESOME ahmedNaguib it WORKED!!!

Thanks so much