jQuery operation input type=checkbox implementation code_jquery

Copy code The code is as follows:

:
2012 The national teams that qualified in the "Group of Death" of the European Cup are:

Germany
Denmark
Netherlands
Portugal

　1. The first and second place in the group qualify, so they are restricted to only two choices.

Copy code The code is as follows:

var len = $("input[name='nation ']:checked").length;
if(len==0) {
alert("Please select the qualifying national team!");
return false;
}else if(len< ;2) {
alert("Please select two national teams!");
return false;
}else if(len>2) {
alert("Only two countries can be selected Team! ");
return false;
}else {
return true;
}

　2. Traverse the selected national teams.

Copy code The code is as follows:

$("input[name='nation']: checked").each(function(){
alert("Selected national team: " $(this).val());
});

　3. Deselect all selected national teams.

Copy code The code is as follows:

$("input[name='nation']:checked") .attr("checked",false);

　4. Specify two national teams.

Copy code The code is as follows:

$("input[name='nation'][ value='Germany']").attr("checked",true);
$("input[name='nation'][value='Holland']").attr("checked",true) ;

　5. It is forbidden to select the national team.

Copy code The code is as follows:

$("input[name='nation']").attr ("disabled",true);

　6. Allow selection of the national team.

Copy code The code is as follows:

$("input[name='nation']").attr ("disabled",false);

7. Select the national team whose index is even or odd (the index starts from 0).

Copy code The code is as follows:

//Select the national team with an even number
$(" input[name='nation']:even").attr("checked",true);
//Select the national team with an odd index
$("input[name='nation']:odd ").attr("checked",true);