Enter Specific Character in the inputbox(prevent user from entering the specific character)

As you can see this image has submit and next question button ,
everytime the user press the submit button a popup message will appear either wrong or correct ,
and you will proceed to the next question.

When you proceed to the next question the index of this array will increment.

Now , my little problem in your code you gave me is that you used ng-repeat instead of using array[index] ,

Just this example , this represents each array[index] and it's maxlength

<input type='text' ng-value={{questions[1].maxCharLength()}}>

All I want to happen is to get the array[index] of each pattern , just like this but this isn't working .

 <input production-qty="{{questions[1].pattern}}" type="text" maxlength="20" ng-model="qty1">