Check if an image size exists

Just went through a question which asked how to check if an image size exists, unfortunately there was no satisfying answer…

Here’s how it can be done,

in_array( 'large', get_intermediate_image_sizes() ); // boolean true

in_array( 'medium_large', get_intermediate_image_sizes() ); // for WP version > 4.4 boolean true, else false

in_array( 'humongous', get_intermediate_image_sizes() ); // boolean false (doesn't exist by default)