Javascript. document.create -

is if statement saying if placeholder not in document.create(input)? why using document.create.

<input type="text" placeholder="john doe"> <input type="email"> <script> if( !'placeholder' in document.createelement('input'){     // } </script>

it's seems trying perform feature detection determine support placeholder properties on <input> elements, new html5.

the document.createelement('input') used create unmodified <input> element test. , in operator tests presence of property on dom element.

though, doesn't quite achieve seems trying. ! act before in, ends testing whether such elements have false properties, don't.

it'll need group of parenthesis ensure in evaluated first ! can negate result condition.

if (!('placeholder' in document.createelement('input'))) {     // `<input>` elements don't have `placeholder` properties }

note: missing closing ) if condition.

Naan