Problem script screenshot
In the highlighted script line numbered as (7) in the pic, condition (!el.placeholder) inside ‘if’ depends on ‘placeholder’ being a implemented as a property of element ‘el’ so that it can have falsy or truthy values. While the basis of this script is to run only when browser does not support ‘placeholder’ property in form elements, it seems to me as an incorrect example.
I am a still a novice self-learner web developer. I just want to make sure if I am correct and this example is wrong according to my understanding. And if I am wrong (book is correct) please kindly explain in detail.