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How to round in Javascript/Angular JS -- but remove insignificant digits


I have a the following statement in my Javascript controller:

$scope.myList = [0, 1, 0.5, 0.6666666];

My AngularJS template contains the following line:

<div ng-repeat="i in myList">{{i}}</div>

This produces the following HTML output:

<div>0</div>
<div>1</div>
<div>0.5</div>
<div>0.6666666</div>

I want the numbers to be rounded to 2 decimal places. However, I would like to see only significant digits in the output. I don't want to see trailing zeroes. How do I do it? Using {{i | number:2}} doesn't eliminate trailing zeroes.


Solution

  • You could just multiple by 1 to convert it to true value.

    <div ng-repeat="i in myList">{{(i | number:2)*1}}</div>
    

    As noted from the comments above solution will break due to the locale formatting by angular number filter. If you need the locale formatting and rounding you could create an extension filter which underneath uses number filter and $locale service.

    .filter('numberEx', ['numberFilter', '$locale',
      function(number, $locale) {
    
        var formats = $locale.NUMBER_FORMATS;
        return function(input, fractionSize) {
          //Get formatted value
          var formattedValue = number(input, fractionSize);
    
          //get the decimalSepPosition
          var decimalIdx = formattedValue.indexOf(formats.DECIMAL_SEP);
    
          //If no decimal just return
          if (decimalIdx == -1) return formattedValue;
    
    
          var whole = formattedValue.substring(0, decimalIdx);
          var decimal = (Number(formattedValue.substring(decimalIdx)) || "").toString();
    
          return whole +  decimal.substring(1);
        };
      }
    ]);
    

    And use it as:

      <div ng-repeat="i in myList">{{i | numberEx:2}}</div>
    

    Demo

    angular.module('app', []).controller('ctrl', function($scope) {
    
      $scope.myList = [0, 10000.56, 0.5, 0.6666666, -1000.23123, 1, 1002, 2.5, 30.5, 22];
    
    }).filter('numberEx', ['numberFilter', '$locale',
      function(number, $locale) {
    
        var formats = $locale.NUMBER_FORMATS;
        return function(input, fractionSize) {
          //Get formatted value
          var formattedValue = number(input, fractionSize);
    
          //get the decimalSepPosition
          var decimalIdx = formattedValue.indexOf(formats.DECIMAL_SEP);
          
          //If no decimal just return
          if (decimalIdx == -1) return formattedValue;
    
     
          var whole = formattedValue.substring(0, decimalIdx);
          var decimal = (Number(formattedValue.substring(decimalIdx)) || "").toString();
          
          return whole +  decimal.substring(1);
        };
      }
    ]);
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.2.23/angular.min.js"></script>
    <div ng-app="app" ng-controller="ctrl">
      <div ng-repeat="i in myList">{{i | numberEx:2}}</div>
    </div>