Angular: Empty Fiddle

http://angularjs.org/

HTML

<script src="http://code.angularjs.org/angular-1.0.1.js"></script>
<div ng-controller="MyCtrl">
<div ng-repeat="pants in players|groupBy:'pants'">
    <b>{{pants}}</b>
</div>
</div>

JavaScript

var myApp = angular.module('myApp',[]);

function MyCtrl($scope) {
    $scope.players = [
        {shirt: 'XXL', pants: '42', shoes: '12'},
        {shirt: 'XL', pants: '38', shoes: '10'},
        {shirt: 'M', pants: '32', shoes: '9'},
        {shirt: 'XXL', pants: '42', shoes: '12'},
        {shirt: 'XXL', pants: '42', shoes: '12'},
        {shirt: 'XXL', pants: '42', shoes: '12'}
    ];
}

var uniqueItems = function (data, key) {
    var result = new Array();
    for (var i = 0; i < data.length; i++) {
        var value = data[i][key];
 
        if (result.indexOf(value) == -1) {
            result.push(value);
        }
    
    }
    return result;
};

myApp.filter('groupBy',
            function () {
                return function (collection, key) {
                    if (collection === null) return;
                    return uniqueItems(collection, key);
        };
    });