What is the use of (“*”) in jquery

问题

I am reading jQuery, i don't know why use ("*") please explain it's helpful

<script>
    $(document).ready(function(){
        $("button").click(function(){
            $("*").hide();
        });
    });
</script>

回答1:

* is a selector in jquery which select everything without any condition including html, head and body.

Here is an example explaining its usage.

$(document).ready(function(){
    $("button").click(function(){
        $("*").hide();
    });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
  Hello text
</div>
<button>Click Me to Hide everything</button>

* selector can be used with elements that it selects all child elements within the specified element. without any condition

$(document).ready(function(){
    $("button").click(function(){
        $("div *").toggle();
    });
});

div{
border:0.5px solid red;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>
  <p>Hello text</p>
  <a>Here is a link </a>
</div>

<button>Click Me to Hide/ Show elements inside the div</button>

回答2:

$(*) is used to select all elements inside the document. Refer this: https://www.w3schools.com/jquery/sel_all.asp

回答3:

$(*) is a selector in jqueryto select all elements

and hence

$("*").hide(); will hide all elements

$(document).ready(function(){
    $("button").click(function(){
        $("*").hide();
    });
});

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<div>Hello</div>
<p>World</p>
<span>Good Morning</span>
<button>Hide</button>

Docs

来源：https://stackoverflow.com/questions/43153792/what-is-the-use-of-in-jquery