How to autocapitalize the first character in an input field in AngularJS?

Yes, you need to define a directive and define your own parser function:

myApp.directive('capitalizeFirst', function($parse) {
   return {
     require: 'ngModel',
     link: function(scope, element, attrs, modelCtrl) {
        var capitalize = function(inputValue) {
           if (inputValue === undefined) { inputValue = ''; }
           var capitalized = inputValue.charAt(0).toUpperCase() +
                             inputValue.substring(1);
           if(capitalized !== inputValue) {
              modelCtrl.$setViewValue(capitalized);
              modelCtrl.$render();
            }         
            return capitalized;
         }
         modelCtrl.$parsers.push(capitalize);
         capitalize($parse(attrs.ngModel)(scope)); // capitalize initial value
     }
   };
});

HTML:

<input type="text" ng-model="obj.name" capitalize-first>

Fiddle

Please remember that not everything needs an Angular solution. You see this a lot with the jQuery crowd; they like to use expensive jQuery functions to do things that are simpler or easier to do with pure javascript.

So while you might very well need a capitalize function and the above answers provide that, it's going to be a lot more efficient to just use the css rule "text-transform: capitalize"

<tr ng-repeat="(key, value) in item">
    <td style="text-transform: capitalize">{{key}}</td>
    <td>{{item}}</td>
</tr>

You can create a custom filter 'capitalize' and apply it to any string you want:

 <div ng-controller="MyCtrl">
     {{aString | capitalize}} !
</div>

JavaScript code for filter:

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

myApp.filter('capitalize', function() {
    return function(input, scope) {
        return input.substring(0,1).toUpperCase()+input.substring(1);
    }
});

Use the CSS :first-letter pseudo class.

You need to put everything lowercase and after apply the uppercase only to the first letter

p{
    text-transform: lowercase;
}
p:first-letter{
    text-transform: uppercase;
}

Here's an example: http://jsfiddle.net/AlexCode/xu24h/