How to get default image sizes attribute

Question

How do I get the height and width of default image sizes? I am not talking about custom image sizes, which can be retrieved from get_intermediate_image_sizes(). I want to get size attribute for 'thumbnail', 'medium', and 'large'.

Update Base on answer by Mridul Aggarwal, looks like i can do:

function get_image_size ($size) {
      return (array(get_option($size. '_size_w'),get_option($size. '_size_h')); 
}

Is this the only way?

Answer 1

If you want to get those set in the admin panel, use the function get_option. The keys are

get_option('thumbnail_size_w');
get_option('thumbnail_size_h');
get_option('medium_size_w');
get_option('medium_size_h');
get_option('large_size_w');
get_option('large_size_h');

If you want them for some specific attachment, use wp_get_attachment_image_src

Answer 2

If you using wp_get_attachment_image_src you can get width and height like this

<img 
    src="<?php $featured_image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( 9999, 9999 ), false, '' ); echo $featured_image[0]; ?>"
    width="<?php echo $featured_image[1]; ?>"
    height="<?php echo $featured_image[2]; ?>" 
/>