Groups examples and some boolean checks corrected

examples/groups/for each.php

@@ -0,0 +1,50 @@
+ 
+ <?php
+    $title = "iterating over a group";
+    require('../head.php');
+?>
+
+<script type="text/javascript">
+
+(function () {
+
+    var game = new Phaser.Game(800, 600, Phaser.CANVAS, '', { preload: preload, create: create,update:update,render : render });
+
+    var baseAlphaIncSpeed= 0.006;
+
+    function preload() {
+        game.load.spritesheet('item', 'assets/buttons/number-buttons-90x90.png', 90, 90);
+        
+    }
+    function create() {
+        // Add some items.
+        for (var i = 0; i < 3; i++) {
+            game.add.sprite(290, 98 * (i + 1), 'item', i)
+                .alphaIncSpeed = baseAlphaIncSpeed * (i + 1);
+            game.add.sprite(388, 98 * (i + 1), 'item', i + 3)
+                .alphaIncSpeed = baseAlphaIncSpeed * (i + 4);
+        }
+    }
+    function update() {
+        // Animating alpha property of each item using forEach() method.
+        game.world.group.forEach(function(item) {
+            // Update alpha first.
+            item.alpha -= item.alphaIncSpeed;
+            // Check for switch between increasing and descreasing.
+            if (item.alpha < 0.001 || item.alpha > 0.999) {
+                item.alphaIncSpeed *= -1;
+            }
+        });
+    }
+    function render() {
+
+        game.debug.renderText('Alpha of items is always changing.', 280, 480);
+    }
+
+})();
+
+</script>
+
+<?php
+    require('../foot.php');
+?>