amirping/index.html

## index.html
<!DOCTYPE html>
<html ng-app="app">

  <head>

    <link rel="stylesheet" href="style.css" />

  </head>

  <body ng-controller="main">
    <h1>Hello Plunker!</h1>
    <textarea ng-model="indata"></textarea>
    <input type="text" ng-model="shift" value="0">
    <button ng-click="crypte()">crypte</button>
    <textarea ng-model="outdata"></textarea>
    <script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.6/angular.min.js"></script>
    <script src="script.js"></script>
  </body>

</html>

## main.js
// Code goes here
angular.module('app', [])
  .controller('main', function($scope) {
    $scope.indata = "abc";
    $scope.outdata = "";
    $scope.shift = 1;
    $scope.crypte = function() {
      $scope.outdata = caesarShift($scope.indata,parseInt($scope.shift));
    }
    var caesarShift = function(str, amount) {

      // Wrap the amount
      if (amount < 0)
        return caesarShift(str, amount + 26);

      // Make an output variable
      var output = '';

      // Go through each character
      for (var i = 0; i < str.length; i++) {

        // Get the character we'll be appending
        var c = str[i];

        // If it's a letter...
        if (c.match(/[a-z]/i)) {

          // Get its code
          var code = str.charCodeAt(i);

          // Uppercase letters
          if ((code >= 65) && (code <= 90))
            c = String.fromCharCode(((code - 65 + amount) % 26) + 65);

          // Lowercase letters
          else if ((code >= 97) && (code <= 122))
            c = String.fromCharCode(((code - 97 + amount) % 26) + 97);

        }

        // Append
        output += c;

      }

      // All done!
      return output;

    };
  });
	<!DOCTYPE html>
	<html ng-app="app">

	<head>

	<link rel="stylesheet" href="style.css" />

	</head>

	<body ng-controller="main">
	<h1>Hello Plunker!</h1>
	<textarea ng-model="indata"></textarea>
	<input type="text" ng-model="shift" value="0">
	<button ng-click="crypte()">crypte</button>
	<textarea ng-model="outdata"></textarea>
	<script src="https://ajax.googleapis.com/ajax/libs/angularjs/1.6.6/angular.min.js"></script>
	<script src="script.js"></script>
	</body>

	</html>
	// Code goes here
	angular.module('app', [])
	.controller('main', function($scope) {
	$scope.indata = "abc";
	$scope.outdata = "";
	$scope.shift = 1;
	$scope.crypte = function() {
	$scope.outdata = caesarShift($scope.indata,parseInt($scope.shift));
	}
	var caesarShift = function(str, amount) {

	// Wrap the amount
	if (amount < 0)
	return caesarShift(str, amount + 26);

	// Make an output variable
	var output = '';

	// Go through each character
	for (var i = 0; i < str.length; i++) {

	// Get the character we'll be appending
	var c = str[i];

	// If it's a letter...
	if (c.match(/[a-z]/i)) {

	// Get its code
	var code = str.charCodeAt(i);

	// Uppercase letters
	if ((code >= 65) && (code <= 90))
	c = String.fromCharCode(((code - 65 + amount) % 26) + 65);

	// Lowercase letters
	else if ((code >= 97) && (code <= 122))
	c = String.fromCharCode(((code - 97 + amount) % 26) + 97);

	}

	// Append
	output += c;

	}

	// All done!
	return output;

	};
	});