Sorting dropdown list using Javascript

Question

i want to sort the drop down items using javascript,can anyone tell me how to do this.

Answer 1

The answers provided didn't really suit my case so I made my own (especially not wanting jQuery). Figured it might help others.

sortDropDown(document.querySelector('select'));

function sortDropDown(d){
    //save option values
    var existingOptions=d.options; 

    //keep track of previously selected option
    var selectedOpt=d.selectedOptions[0].value;

    //turn nodeList into Array of values
    existingOptions=[].slice.call(existingOptions).map(function(a){return a.innerText});

    //make sure options are unique
    existingOptions = existingOptions.filter( function(value, index, self) { 
        return self.indexOf(value) === index;
    }); 

    //sort options
    existingOptions.sort();

    //keep "All" option as first element
    existingOptions.splice(0, 0, existingOptions.splice(existingOptions.indexOf('All'), 1)[0]);

    //repleace dropdown contents
    var t='';
    existingOptions.forEach(function(a){
        t+=''+a+'';
    });
    d.innerHTML=t;
}