$("select").change(function(){
var n = $(this).children().length;
var obj;
var i = 1;
$(this).children().each(function(){
if(i == n)
{
alert($(this).text());
}
i ;
});
});
Based on the above two methods, I easily got the effect I wanted, as follows:
function selectall()
{
$("select").children().each(function(){$(this).attr("selected" ,"selected")})
}
Used children() and $(this).attr("selected","selected") respectively
A js usage
![[Web front-end] Node.js quick start](https://img.php.cn/upload/course/000/000/067/662b5d34ba7c0227.png)
