The following is an extension method, so you can call it like this: sb.TrimEnd(); Also, it returns the SB instance, allowing you to chain other calls (sb.TrimEnd().AppendLine()). public static StringBuilder TrimEnd(this StringBuilder sb) { if (sb == null || sb.Length == 0) return sb; int i = sb.Length – 1; for (; i >= 0; … Read more
Just wrap it in a FileStream. StreamWriter sw = new StreamWriter( new FileStream(saveFileDialog1.FileName, FileMode.Open, FileAccess.ReadWrite), Encoding.UTF8 ); If you want to append, use FileMode.Append instead. You should also call Dispose() on a try/finally block, or use a using block to dispose the object when it exceeds the using scope: using( var sw = new StreamWriter( … Read more
I made the code change and yes it made a huge difference in number of allocations (GetEnumerator()) calls vs not. Imagine this code is millions of times per second. The number of enumerators allocated is ridiculous and can be avoided. edit: We now invert control in order to avoid any allocations (writing to the writer … Read more
As you apparently already know, StringBuilder inherits equals() from java.lang.Object, and as such StringBuilder.equals() returns true only when passed the same object as an argument. It does not compare the contents of two StringBuilders! If you look at the source, you’ll conclude that the most efficient comparison (that didn’t involve creating any new objects) would … Read more
The StringBuilder class has a special version of the ToString method that takes two arguments, exactly as Substring(startIndex, length). StringBuilder sb = new StringBuilder(“This is a Test”); string test = sb.ToString(10, 4); Console.WriteLine(test); // result = Test
For String, StringBuffer, and StringBuilder, charAt() is a constant-time operation. For StringBuffer and StringBuilder, deleteCharAt() is a linear-time operation. StringBuffer and StringBuilder have very similar performance characteristics. The primary difference is that the former is synchronized (so is thread-safe) while the latter is not.
Absolutely not; here’s a simple example lifted from 4.0 via reflector: [SecuritySafeCritical] public StringBuilder Append(char value) { if (this.m_ChunkLength < this.m_ChunkChars.Length) { this.m_ChunkChars[this.m_ChunkLength++] = value; } else { this.Append(value, 1); } return this; } The attribute just handles callers, not thread-safety; this is absolutely not thread-safe. Update: looking at the source he references, this is … Read more
It is true that StringBuilder tends to be better than concatenating or modifying Strings manually, since StringBuilder is mutable, while String is immutable and you need to create a new String for each modification. Just to note, though, the Java compiler will automatically convert an example like this: String result = someString + someOtherString + … Read more
What is the possible use of StringWriter and StringReader, which cannot be done by StringBuilder itself? StringReader and StringWriter derive from TextReader and TextWriter respectively. So what they can do act as a TextReader or TextWriter instance, which string or StringBuilder cannot because they do not derive either of those types. What is the practical … Read more
Sorted by efficiency: Counting your AppendLine() calls Calling IndexOf() in a loop Using Regex Using String.Split() The last one is extraordinary expensive and generates lots of garbage, don’t use.