christopherhill/Public and Private Methods with Testing Example

## Public and Private Methods with Testing Example
<!DOCTYPE html>

<html>

<head>
    <title>MJ Test</title>
    <style>
        .passed { color: green; }
        .failed { color: red; }

        .sample-code {
            border: 1px dashed gray;
            background-color: #eeeeee;
            padding: 10px;
        }
    </style>
    <script src="https://code.jquery.com/jquery-2.1.0.min.js"></script>
</head>

<body>

<h1>Build a simple set</h1>
<p>Implement a simple Set object in Javascript.  For simplicity, the Set stores only Strings.  The Set should support the following API:</p>
<pre class="sample-code">
    var set = new Set();        // instantiates a new Set
    set.add("someKey");         // stores 'someKey' in the set.  add() returns true if the key was added; false otherwise.
    set.count();                // returns the number of keys in the set.
    set.contains("someKey");    // returns true if the key is in the set; false otherwise.
    set.remove("someKey");      // deletes the key from the set.  delete() returns true if the key was removed; false otherwise.
</pre>

What's included: jQuery and an assertion method called assertEqual that we use for simple tests.  Refer to the code below for an
example of how to use assertEqual().

Suggestion/hint:  You will need some data structure to store the items in the set.  This should be a private variable.

<ul class="assertion-results">

</ul>

<script>

    "use strict";

    function assertEqual(actual, expected, message) {
        var results = $(".assertion-results");
        var css = (actual === expected) ? 'passed' : 'failed';
        var fullMsg = (actual === expected) ? message : message + ' - FAILED: expected ' + expected + ' but was ' + actual;
	      results.append("<li class='" + css + "'>" + fullMsg + "</li>");
    }

    assertEqual(1, 1, 'This should pass');
    assertEqual(true, false, 'This will fail');

    function Set() {

        // private variables
        var struct = [];

        // public variables and methods
        var publics = {};

        publics.add = function(key) {
          // only add if not already present and a string
          if (typeof(key) === 'string') {
          	if (!publics.contains(key)) {
              if (struct.push(key)) {
                return true;
              } else {
                return false;
              }
            }
          }
        }

        publics.count = function() {
          return struct.length;
        }

        publics.contains = function(key) {
        	// use $.inArray for x-browser
          return $.inArray(key, struct) >= 0 ? true : false;
        }

        publics.remove = function(key) {
          var index = $.inArray(key, struct);
          if (index >= 0) {
              if (struct.splice(index, 1)) {
                  return true;
              } else {
                  return false;
              }
          }
        }

        // return closure of public methods
        return publics;

    }

    var set = new Set();
    assertEqual(set.count(), 0, 'Set starts out empty');

    set.add("panda");
    assertEqual(set.count(), 1, "Count should be 1");

    set.add("panda");
    assertEqual(set.count(), 1, "Count should still be 1");

    set.add("tiger");
    assertEqual(set.count(), 2, "Count should now be 2");

    assertEqual(set.contains("panda"), true, "Set should contain 'panda'");
    assertEqual(set.contains("tiger"), true, "Set should contain 'tiger'");
    assertEqual(set.contains("lemur"), false, "Set should not contain 'lemur'");

    set.remove("panda");
    assertEqual(set.contains("panda"), false, "Set no longer contains 'panda'");

</script>

</body>
</html>
	<!DOCTYPE html>

	<html>

	<head>
	<title>MJ Test</title>
	<style>
	.passed { color: green; }
	.failed { color: red; }

	.sample-code {
	border: 1px dashed gray;
	background-color: #eeeeee;
	padding: 10px;
	}
	</style>
	<script src="https://code.jquery.com/jquery-2.1.0.min.js"></script>
	</head>

	<body>

	<h1>Build a simple set</h1>
	<p>Implement a simple Set object in Javascript. For simplicity, the Set stores only Strings. The Set should support the following API:</p>
	<pre class="sample-code">
	var set = new Set(); // instantiates a new Set
	set.add("someKey"); // stores 'someKey' in the set. add() returns true if the key was added; false otherwise.
	set.count(); // returns the number of keys in the set.
	set.contains("someKey"); // returns true if the key is in the set; false otherwise.
	set.remove("someKey"); // deletes the key from the set. delete() returns true if the key was removed; false otherwise.
	</pre>

	What's included: jQuery and an assertion method called assertEqual that we use for simple tests. Refer to the code below for an
	example of how to use assertEqual().

	Suggestion/hint: You will need some data structure to store the items in the set. This should be a private variable.

	<ul class="assertion-results">

	</ul>

	<script>

	"use strict";

	function assertEqual(actual, expected, message) {
	var results = $(".assertion-results");
	var css = (actual === expected) ? 'passed' : 'failed';
	var fullMsg = (actual === expected) ? message : message + ' - FAILED: expected ' + expected + ' but was ' + actual;
	results.append("<li class='" + css + "'>" + fullMsg + "</li>");
	}

	assertEqual(1, 1, 'This should pass');
	assertEqual(true, false, 'This will fail');

	function Set() {

	// private variables
	var struct = [];

	// public variables and methods
	var publics = {};

	publics.add = function(key) {
	// only add if not already present and a string
	if (typeof(key) === 'string') {
	if (!publics.contains(key)) {
	if (struct.push(key)) {
	return true;
	} else {
	return false;
	}
	}
	}
	}

	publics.count = function() {
	return struct.length;
	}

	publics.contains = function(key) {
	// use $.inArray for x-browser
	return $.inArray(key, struct) >= 0 ? true : false;
	}

	publics.remove = function(key) {
	var index = $.inArray(key, struct);
	if (index >= 0) {
	if (struct.splice(index, 1)) {
	return true;
	} else {
	return false;
	}
	}
	}

	// return closure of public methods
	return publics;

	}

	var set = new Set();
	assertEqual(set.count(), 0, 'Set starts out empty');

	set.add("panda");
	assertEqual(set.count(), 1, "Count should be 1");

	set.add("panda");
	assertEqual(set.count(), 1, "Count should still be 1");

	set.add("tiger");
	assertEqual(set.count(), 2, "Count should now be 2");

	assertEqual(set.contains("panda"), true, "Set should contain 'panda'");
	assertEqual(set.contains("tiger"), true, "Set should contain 'tiger'");
	assertEqual(set.contains("lemur"), false, "Set should not contain 'lemur'");

	set.remove("panda");
	assertEqual(set.contains("panda"), false, "Set no longer contains 'panda'");

	</script>

	</body>
	</html>