String Builder & String, what's the difference ?

[Tee]

String Builder & String, what's the difference.
and when to use which ?
Thanks.

[Craig Deelsnyder]

On Fri, 25 Jun 2004 10:24:00 +0800, Tee <th*@streamyx.c om> wrote:

String Builder & String, what's the difference.
and when to use which ?
Thanks.

Basically String is fine for never-changing values; but if you create a
'string-like' variable and need to change it's value (such as
concatenating a string value together) use StringBuilder:

http://msdn.microsoft.com/library/en...ilderclass.asp
--
Craig Deelsnyder
Microsoft MVP - ASP/ASP.NET

[Donald E. Hurley Jr.]

Strings are immutable. Meaning if you try to: string1 = string1 + string2,
it needs to create a new memory location for string1 and set the original
location for GC.

StringBuilder does not behave this way.

Don

"Tee" <th*@streamyx.c om> wrote in message
news:#U******** ******@tk2msftn gp13.phx.gbl...

String Builder & String, what's the difference.
and when to use which ?
Thanks.

[Saul]

Tee,

Here's my take on it :

Use stringbuilder whenever you need to do LOTS of string manipulations. For
quick/little things, I don't bother. So if I'm just adding a string in one
line I would do something like this --

strA = strB & strC

However, I had a loop where I was doing about 1,200 concatinations. Using
string builder reduced the time this took substantially.

Others may feel different, but this works for me.

-Saul
"Tee" <th*@streamyx.c om> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

String Builder & String, what's the difference.
and when to use which ?
Thanks.

[Saul]

Tee,

Here's my take on it :

Use stringbuilder whenever you need to do LOTS of string manipulations. For
quick/little things, I don't bother. So if I'm just adding a string in one
line I would do something like this --

strA = strB & strC

However, I had a loop where I was doing about 1,200 concatinations. Using
string builder reduced the time this took substantially.

Others may feel different, but this works for me.

-Saul
"Tee" <th*@streamyx.c om> wrote in message
news:%2******** ********@tk2msf tngp13.phx.gbl. ..

String Builder & String, what's the difference.
and when to use which ?
Thanks.

[Kevin Spencer]

> in a few words - stringbuilder is much faster! use it as often as you can
instead

Odd that Microsoft doesn't recommend it that way...

Once a StringBuilder class is instantiated, it is indeed much faster.
However, the instantiation of an Object is costly in itself. A String is a
primitive, which means that unless you treat it as an object, it is
certainly much faster to use than an Object (which is why the .Net framework
includes primitives). In addition, when you instantiate a StringBuilder, it
allocates the default amount of Memory needed to hold its entire buffer (the
buffer is how it avoids re-allocating Memory). Therefore, if you are doing a
small amount of work with a string, it may indeed more efficient NOT to use
a StringBuilder. Consider the following:

StringBuilder s = new StringBuilder(" Hello Mom").;
s.Append(", I mean, Mother");
Response.Write( s.ToString());

string s = "Hello Mom";
s += ", I mean, Mother";
Response.Write( s);

Which runs faster? Which uses the most Memory?

--
HTH,
Kevin Spencer
..Net Developer
Microsoft MVP
Big things are made up
of lots of little things.

"ISK" <IS*@discussion s.microsoft.com > wrote in message
news:43******** *************** ***********@mic rosoft.com...

in a few words - stringbuilder is much faster! use it as often as you can instead of the regular string especially if you are doing a lot of string manipulations.
a little more in depth - a string is 'unchangeable' in the sense that once you've assigned a value to it, it never changes; any modifications you make to it like say adding more characters, appending a string or trimming it etc will create a new string object and assign the modified value to it and discard the old string object leaving it for the GC to take care of during its collection routines.. so a lot of string manipulation means a lot of allocation de-allocation of memory which isn't very efficient..obvi ously this also means that the methods like s3 = s1 & s2 are slower than you would expect..

on the other hand, the stringbuilder creates a sort of buffer (default is 128 chars but u can change it with its overloaded constructor) and whenever you use the 'append' method, it adds the appended character(s) or string to the created buffer...thus there is no creation-destruction of objects on the fly which means its much faster..

just to give you an idea..the operation s1 = s1 & s2 is almost 100 times slower than stringbuilder1 = stringbuilder1. append(s2) (assuming s1 and stringbuilder1 are of same lengths) even for the smallest of lengths of s1 and s2 (run the operations in a loop of say like a hundred thousand to notice the difference)
hope this helps..

"Tee" wrote:

String Builder & String, what's the difference.
and when to use which ?
Thanks.

[Tom Shelton]

On Fri, 25 Jun 2004 13:24:21 -0400, Kevin Spencer wrote:

in a few words - stringbuilder is much faster! use it as often as you can instead

Odd that Microsoft doesn't recommend it that way...

They do.

http://msdn.microsoft.com/library/de...etperftips.asp

see the section: Use StringBuilder for Complex String Manipulation
Once a StringBuilder class is instantiated, it is indeed much faster.
However, the instantiation of an Object is costly in itself. A String is a
primitive, which means that unless you treat it as an object, it is
Not true. Strings are reference types (not "primitives ). The only reason
a string MAY be faster to instantiate is because it doesn't allocate a
buffer, it simply allocates a 4-byte pointer and sets it to null. Where as
a stringbuilder will allocate an initial buffer (though the default buffer
size is only sixteen characters).
certainly much faster to use than an Object (which is why the .Net framework
includes primitives).
Strings are objects.
In addition, when you instantiate a StringBuilder, it
allocates the default amount of Memory needed to hold its entire buffer (the
The initial buffer (unless specified) is only sixteen characters...
buffer is how it avoids re-allocating Memory). Therefore, if you are doing a
small amount of work with a string, it may indeed more efficient NOT to use
a StringBuilder. Consider the following:

StringBuilder s = new StringBuilder(" Hello Mom").;
s.Append(", I mean, Mother");
Response.Write( s.ToString());

string s = "Hello Mom";
s += ", I mean, Mother";
Response.Write( s);

Which runs faster? Which uses the most Memory?

For this example, a stringbuilder would be overkill. But, put it in a loop
or do more then 15 or 20 appends on the string... StringBuilder will
probably come out the winner in both speed and memory - because with a
regular string, there are temporary string objects being created in the
background when you concatenate.

--
Tom Shelton [MVP]

[Kevin Spencer]

Tom, Tom, Tom. Note the exception that I made. You stated (and I quoted, and
now quote):

in a few words - stringbuilder is much faster! use it as often as you

can

instead
By your own admission, my example proves this statement to be false:
Which runs faster? Which uses the most Memory?
For this example, a stringbuilder would be overkill.

I'm not into debate. Just trying to clear the air.

--
HTH,
Kevin Spencer
..Net Developer
Microsoft MVP
Big things are made up
of lots of little things.

"Tom Shelton" <to*@YOUKNOWTHE DRILLmtogden.co m> wrote in message
news:1c******** *************** *****@40tude.ne t... On Fri, 25 Jun 2004 13:24:21 -0400, Kevin Spencer wrote:
in a few words - stringbuilder is much faster! use it as often as you

can instead

Odd that Microsoft doesn't recommend it that way...

They do.

http://msdn.microsoft.com/library/de...etperftips.asp
see the section: Use StringBuilder for Complex String Manipulation

Once a StringBuilder class is instantiated, it is indeed much faster.
However, the instantiation of an Object is costly in itself. A String is a primitive, which means that unless you treat it as an object, it is
Not true. Strings are reference types (not "primitives ). The only reason
a string MAY be faster to instantiate is because it doesn't allocate a
buffer, it simply allocates a 4-byte pointer and sets it to null. Where

as a stringbuilder will allocate an initial buffer (though the default buffer
size is only sixteen characters).

certainly much faster to use than an Object (which is why the .Net framework includes primitives).
Strings are objects.

In addition, when you instantiate a StringBuilder, it
allocates the default amount of Memory needed to hold its entire buffer (the
The initial buffer (unless specified) is only sixteen characters...

buffer is how it avoids re-allocating Memory). Therefore, if you are

doing a small amount of work with a string, it may indeed more efficient NOT to use a StringBuilder. Consider the following:

StringBuilder s = new StringBuilder(" Hello Mom").;
s.Append(", I mean, Mother");
Response.Write( s.ToString());

string s = "Hello Mom";
s += ", I mean, Mother";
Response.Write( s);

Which runs faster? Which uses the most Memory?

For this example, a stringbuilder would be overkill. But, put it in a

loop or do more then 15 or 20 appends on the string... StringBuilder will
probably come out the winner in both speed and memory - because with a
regular string, there are temporary string objects being created in the
background when you concatenate.

--
Tom Shelton [MVP]

[Cor Ligthert]

Hi Tom,

I was always using
dim sb as new stringbuilder
sb.append("Hell o")
sb.append(" how ")
sb.append("are you?")

Than Fergus ask me once, why you do that, this is overkill? I tested it,
and the difference was almost nothing, and therefore I stopped to show it
this way forever (with long strings I always show/do it like above) and did
it with shortstrings as above no more. Then some weeks ago, Jay B stated to
me, that it was faster to do it as above. (You understand it probably, the
fire was on).

To be sure I tested it again in a very long loop, making a long string from
it and making this as short strings (however 100000 times or so). It is
always faster than concatenating the string, so I use this above again.

:-)

Cor

[Jay B. Harlow [MVP - Outlook]]

Cor,

it with shortstrings as above no more. Then some weeks ago, Jay B stated to me, that it was faster to do it as above. (You understand it probably, the
fire was on). Please do not take things I say out of context!

I'm not sure which thread you think I told you that, but its obvious to me
you are mis-quoting me!

Thanks
Jay

"Cor Ligthert" <no**********@p lanet.nl> wrote in message
news:uB******** ******@TK2MSFTN GP11.phx.gbl... Hi Tom,

I was always using
dim sb as new stringbuilder
sb.append("Hell o")
sb.append(" how ")
sb.append("are you?")

Than Fergus ask me once, why you do that, this is overkill? I tested it,
and the difference was almost nothing, and therefore I stopped to show it
this way forever (with long strings I always show/do it like above) and did it with shortstrings as above no more. Then some weeks ago, Jay B stated to me, that it was faster to do it as above. (You understand it probably, the
fire was on).

To be sure I tested it again in a very long loop, making a long string from it and making this as short strings (however 100000 times or so). It is
always faster than concatenating the string, so I use this above again.

:-)

Cor