how to select few json values in drop down in angularjs

Question

i am getting a data from json file and the values using in dropdown but i dont want to use all values,I want to select only three values in my dropdown.

Answer 1

You can filter the list at the time of feeding it to the dropdown.

<select ng-model="toType" class="form-control" required ng-change="ConvertCurrency()" 
ng-options="k for (k, v) in (rates | 'yourfilter') track by v"></select>

[UPDATE]

I tried to access the API, and found out that res.data.rates is an object and not an array.

So if you only have to show these 3 values, the easy approach would be to create a new array in controller:

var ratesToDisplay = []; 
ratesToDisplay.push({rate:'USD', value: res.data.rates.USD});
ratesToDisplay.push({rate:'EUR', value: res.data.rates.EUR});
ratesToDisplay.push({rate:'CAD', value: res.data.rates.CAD});

and feed this new filtered array to your dropdown.

  <select ng-model="selectedRate" ng-options="rate.value as rate.rate for rate in ratesToDisplay">
    <option value="" disabled>Please Select</option>
  </select>

I hope this helps.

For 2nd part of your problem

You can implement the ng-change() method and call the API from that method. Ex:

    function onDDChange(){
     $http.get('http://api.fixer.io/latest?' + $scope.fromType.label)
.then(function(res) { \\logic for success call back 
    \\ call convert currency method from here.
    });
    } 

HTML:

    <select ng-model="fromType" class="form-control" required 
ng-change="onDDChange()" ng-options="f as f.label for f in rates">