Wie Werte in meinem Json-Objekt zu sortieren

Question

Ich möchte "Jahre" in yearObject des Typs Object sortieren, so dass das Menü mit 2016 statt 2013 beginnt. Bitte helfen. Example Code wird hier bereitgestellt.

Mein HTML:

<form name="myform" id="myForm"> 
      <select name="optone" id="yearSel" size="1"> 
       <option value="" selected="selected">Select Year</option> 
      </select> 
      <br> 
      <br> 
      <select name="opttwo" id="stateSel" size="1"> 
       <option value="" selected="selected">Please select year first</option> 
      </select> 
      <br> 
      <br> 
      <select name="optthree" id="citySel" size="1" citySel.onchange = function();> 
      <option value="" selected="selected">Please select state first</option> 
     </select> 
    </form> 

Mein JS:

var yearObject = { 
    "2016": { 
     "California": ["Los Angeles", "San Francisco"], 
     "Florida": ["Orlando", "Miami"], 
     "New York": ["Manhattan","Brooklyn"] 
    }, 
    "2015": { 
     "California": ["Los Angeles", "San Francisco"], 
     "Florida": ["Orlando", "Miami"], 
     "New York": ["Manhattan","Brooklyn"] 
    }, 
    "2014": { 
     "California": ["Los Angeles", "San Francisco"], 
     "Florida": ["Orlando", "Miami"], 
     "New York": ["Manhattan","Brooklyn"] 
    }, 
    "2013": { 
     "California": ["Los Angeles", "San Francisco"], 
     "Florida": ["Orlando", "Miami"], 
     "New York": ["Manhattan","Brooklyn"] 
    } 
} 
window.onload = function() { 
    var yearSel = document.getElementById("yearSel"), 
     stateSel = document.getElementById("stateSel"), 
     citySel = document.getElementById("citySel"); 
    for (var year in yearObject) { 
     yearSel.options[yearSel.options.length] = new Option(year, year); 
    } 
    yearSel.onchange = function() { 
     stateSel.length = 1; // remove all options bar first 
     citySel.length = 1; // remove all options bar first 
     if (this.selectedIndex < 1) { 
      stateSel.options[0].text = "Please select Year first" 
      citySel.options[0].text = "Please select state first" 
      return; // done 
     } 
     stateSel.options[0].text = "Please select state" 
     for (var state in yearObject[this.value]) { 
      stateSel.options[stateSel.options.length] = new Option(state, state); 
     } 
     if (stateSel.options.length==2) { 
      stateSel.selectedIndex=1; 
      stateSel.onchange(); 
     } 

    } 
    yearSel.onchange(); // reset in case page is reloaded 
    stateSel.onchange = function() { 
     citySel.length = 1; // remove all options bar first 
     if (this.selectedIndex < 1) { 
      citySel.options[0].text = "Please select state first" 
      return; // done 
     } 
     citySel.options[0].text = "Please select city" 

     var cities = yearObject[yearSel.value][this.value]; 
     for (var i = 0; i < cities.length; i++) { 
      citySel.options[citySel.options.length] = new Option(cities[i], cities[i]); 
     } 
     if (citySel.options.length==2) { 
      citySel.selectedIndex=1; 
      citySel.onchange(); 
     } 

    } 
citySel.onchange = function(){ 
    switch(citySel.value){ 

case "Los Angeles": 
     if(yearSel.value == "2016"){ 
     location.href="http://google.com"; 
}else if(yearSel.value == "2015","2014"){ 
     location.href= "http://facebook.com"; 
    } 
break; 
case "Miami": 
     if(yearSel.value == "2016","2015"){ 
     location.href="http://google.com"; 
}else if(yearSel.value == "2014","2013"){ 
     location.href= "http://facebook.com"; 
    } 
break; 
    } 
    } 
    } 

Answer 1

Sie müssen sich für year separaten Array erstellen und sortieren es sort() Funktion in Javascript.

var sortable = []; 
for (var year in yearObject) { 
    sortable.push(year); 
} 
sortable.sort(function(a, b){return b-a}); 
for (var i = 0; i < sortable.length; i++){ 
    yearSel.options[yearSel.options.length] = new Option(sortable[i], sortable[i]); 
} 

Werfen Sie einen Blick auf die Fiddle