JSFiddle - React, Tailwind, and code Playground

HTML

<div ng-app="MyReverseModule" ng-controller="Ctrl">
    <input ng-model="greeting" type="greeting">
    <br>No filter: {{greeting }}
    <br>Reverse: {{greeting|reverse }}
    <br>Reverse + uppercase: {{greeting|reverse:true }}
    <br>
</div>

JavaScript

angular.module( 'MyReverseModule', []).
    filter( 'reverse', function () {
        return function (input, uppercase) {
            var out = "" ;
            for (var i = 0; i < input.length; i++) {
                out = input.charAt(i) + out;
            }
            // conditional based on optional argument
            if (uppercase) {
                out = out.toUpperCase();
            }
            return out;
        }
    });
function Ctrl($scope) {
    $scope.greeting = 'hello' ;
}