added examples

Author: spelluru

articles/event-grid/event-filtering.md

@@ -164,9 +164,64 @@ The same key can be used in more than one filter.
 ```json
 "advancedFilters": [{
     "operatorType": "StringContains",
-    "key": "Subject",
+    "key": "data.key1",
     "values": [
-        "/providers/microsoft.devtestlab/"
+        "microsoft", 
+        "azure"
+    ]
+}]
+```
+
+### StringBeginsWith
+
+```json
+"advancedFilters": [{
+    "operatorType": "StringBeginsWith",
+    "key": "data.key1",
+    "values": [
+        "event", 
+        "grid"
+    ]
+}]
+```
+
+### StringEndsWith
+
+```json
+"advancedFilters": [{
+    "operatorType": "StringEndsWith",
+    "key": "data.key1",
+    "values": [
+        "jpg", 
+        "jpeg", 
+        "png"
+    ]
+}]
+```
+
+### StringIn
+
+```json
+"advancedFilters": [{
+    "operatorType": "StringIn",
+    "key": "data.key1",
+    "values": [
+        "exact", 
+        "string", 
+        "matches"
+    ]
+}]
+```
+
+### StringNotIn
+
+```json
+"advancedFilters": [{
+    "operatorType": "StringNotIn",
+    "key": "data.key1",
+    "values": [
+        "aws", 
+        "bridge"
     ]
 }]
 ```