jquery uses bits and pieces of function code_jquery

1. Simple button js events are used to judge and display prompts

Copy code The code is as follows:

2. Processing of drop-down lists

Copy code The code is as follows:

function dropTypeChange()
{
var sel = $("#<%=dropType.ClientID %> option:selected").val();
if(sel== "-1")
{
$("#<%=txtNo.ClientID %>").attr('disabled',true);
}
else
{
$("#<%=txtNo.ClientID %>").attr('disabled',false);
}
}

/ /Get the value of the first option
$('#test option:first').val();
//The value of the last option
$('#test option:last'). val();
//Get the value of the second option
$('#test option:eq(1)').val();
//Get the selected value
$ ('#test').val();
$('#test option:selected').val();
//Set the option with value 2 to the selected state
$('# test').attr('value','2');
//Set the first option to be selected
$('#test option:last').attr('selected','selected' );
$("#test").attr('value' , $('#test option:last').val());
$("#test").attr('value ' , $('#test option').eq($('#test option').length - 1).val());
//Get the length of select
$('#test option ').length;
//Add an option
$("#test").append("ff");
$( "ff").appendTo("#test");
//Add and remove selected items
$('#test option:selected'). remove();
//The specified item is selected
$('#test option:first').remove();
//The specified value is deleted
$('#test option') .each(function(){
if( $(this).val() == '5'){
$(this).remove();
}
});
$('#test option[value=5]').remove();
//Get the label of the first Group
$('#test optgroup:eq(0)').attr ('label');
//Get the value of the first option under the second group
$('#test optgroup:eq(1) :option:eq(0)').val();