jQuery如何确保用户已为表单上的所有选择菜单选择一个值

Question

i have a form with multiple select menus i want to make sure on submit that a user selected a value for each select menu how can i do that with jquery ? i tried something like

var form = $('myform');
if($(form ).find('select').length != $(form).find('select:option[selected="selected"]').length ) { 
    alert('wrong please make sure to select all select menu');
}

but no luck

please help

Thank you

Answer 1

The form object has already been created.I removed the $() function from the form variables in the if statement. You should also be using an identifier for myform .

var form = $('form#myform');
if(form.find('select').length != form.find('select:option[selected="selected"]').length ) { 
    alert('wrong please make sure to select all select menu');
}

I recommend you prefix your form var with a $ to note that you are already using a jquery object.

Example:

var $form = $('form#myform');
if($form.find('select').length != $form.find('select:option[selected="selected"]').length ) { 
    alert('wrong please make sure to select all select menu');
}

Answer 2

By default select element's first option is selected if none of the options have selected attribute, so your selector will not work which is looking for selected attribute in the option element. Also if the id of the form is myform then you should use #myform to find it. Try this.

var $form = $('#myform');
if($form.find('select').length != $form.find('select:option:selected').length ) { 
    alert('wrong please make sure to select all select menu');
}