Check if a input box is empty

Question

How can I check if a given input control is empty? I know there is $pristine property on the field which tells that if a given field is empty initially but what

Answer 1

Even you don't need to measure the length of string. A ! operator can solve everything for you. Remember always: !(empty string) = true !(some string) = false

So you could write:

Sorry, the field is empty!
Thanks. Successfully validated!