Changes between Version 3 and Version 4 of StringBuilder

Timestamp:

02/01/14 13:10:25 (11 years ago)

Author:

hopscc

Comment:

--

StringBuilder

@@ -23 +23 @@
 }}}
 
-For more information on the StringBuilder class, see [http://www.google.com/search?hl=en&q=C%23+stringbuilder Google(C# StringBuilder)]
+The vernacular notation is something like
+
+{{{
+sb = StringBuilder()
+seperator = ''
+for <someloop>
+    value = ... some calc or marshalling
+    sb.append(sep)
+    sep = ',' # or whatever separator is between items
+    sb.append(value)
+s = sb.toString  # turn into a string for subsequent use
+}}}
+
+= A note about performance =
+With string immutability and wrt .Net/C# conventional wisdom has it that use of a !StringBuilder is faster/better performance wise than just catenating to a String type but it depends....
+    
+    * True, !StringBuilder append is 915-2000x faster than String append but for small strings the overhead of !StringBuilder create 
+      (and conversion back to String) is much higher (150-180x) than just String create/append...
+    * Putting a single string in a !StringBuilder is about 1.6x speed of String doing the same.
+      - i.e String append ( {{{ s='...' s+='...'...}}} ) is FASTER than ( {{{ sb=StringBuilder('...'  s.append('...' ...}}} )
+
+   * create/append...2 strings in !StringBuilder about same (1.02) speed of String doing same
+   * create/append...3,4 strings in !StringBuilder faster (0.92, .8) speed than that of String doing same
+    (Without conversion !StringBuilder back to String)
+
+  Implies use String if appending <=2 strings, !StringBuilder for more and using result directly[[BR]]
+ 
+    Full Cycle: create, append, convert to String[[BR]]
+        * create, convert to string - using String is about 200x faster than using a !StringBuilder
+        * create, append 1 string, convert to String - String about 1.9x faster than !StringBuilder
+            - conversion !StringBuilder to String overhead is about 0.3
+        * create, append 2 strings, convert to String - using String about 1.13x faster than using !StringBuilder
+        * create, append 3 strings, convert to String - using String about 1.2x faster than !StringBuilder
+        * create, append 4 strings, convert to String - using String about same (.96, 1.04 slower) speed as  using !StringBuilder 
+        * create, append 5 strings, convert to string - using String about 0.86 (1.2 slower) than !StringBuilder
+
+  Implies that it is faster to use String if expecting to append <=4 strings, otherwise use a !StringBuilder ...
+
+
+For more information on the StringBuilder class, see [http://www.google.com/search?hl=en&q=C%23+stringbuilder Google(C# !StringBuilder)]
 
 See also: LibraryTopics