<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Title</title>
<script src="jquery-3.3.1.min.js"></script>
</head>
<body>
<p style="display:none">hello world</p>
<input type="button" id="show" value="显示">
<input type="button" id="hide" value="隐藏">
<input type="button" id="toggle" value="toggle">
</body>
<script>
$("#show").click(function(){
$("p").show()
})
$("#hide").click(function(){
$("p").hide()
})
$("#toggle").click(function(){
$("p").toggle()
})
</script>
</html>