See the difference between the. Val () and. attr ("value") of jquery from the Reset input file label _jquery

Background:

When the input file label is emptied, the following methods are used to find some errors:

"√" $ ("#file") [0].value = "";
"√" $ ("#file") [0].value = null;

"X" $ ("#file"). attr ("Value", "");
"X" $ ("#file"). attr ("value", null);
"√" $ ("#file"). Val ("");
"√" $ ("#file"). val (null);

Why is the same change in value, the result is different?

Explanation:

Check out the StackOverflow jQuery. Val () vs. attr ("value") question, which answers the following:

The gist is this. attr (...) is the objects value at the start (when the HTML is created). Val () is getting the "object" property value which can change many times.

Translation is:

. Val () sets the value attribute of input, input is an instance of Htmlinputelement, value is defined by setter method, when assigned, the value is written into input, and the method of changing the Value property The actual operation is the Value property of the DOM, which triggers the browser's repaint and updates the input value.

The above is a small set for you to introduce the aggravating input file label to see jquery. val () and. attr ("value") difference, hope to help everyone, if you have any questions please give me a message, small series will promptly reply to everyone. Here also thank you very much for the cloud Habitat Community website support!