Which string is more preferred
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Number 2 is the right way, number 1 is the wrong way and number 3 does something entirely different to 1 & 2 (It does not assign a variable to lblScore). If it did assign str.ToString() to lblScore then it would be mostly the same as 2, but with the worthless overhead of creating a StringBuilder. If however you were appending a greater number of strings to the output then 3 would be the better way to approach the problem.
j4amieC you are write I did not write the full code in the third case, but yes the StringBuilder does assign the text to the lblScore. Can you tell me why concatenating strings is not a good idea in this case. Does it leave string objects in memory? Or is there any other reason?
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j4amieC you are write I did not write the full code in the third case, but yes the StringBuilder does assign the text to the lblScore. Can you tell me why concatenating strings is not a good idea in this case. Does it leave string objects in memory? Or is there any other reason?
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I would disagree, its a matter of preference. I see nothing wrong with something like "Some string: " + x, depending on the circumstance it is being used in. As Guffa points out there may be some boxing that is occurring with StringBuilder and Format which could be avoided.
only two letters away from being an asset
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Number 2 is the right way, number 1 is the wrong way and number 3 does something entirely different to 1 & 2 (It does not assign a variable to lblScore). If it did assign str.ToString() to lblScore then it would be mostly the same as 2, but with the worthless overhead of creating a StringBuilder. If however you were appending a greater number of strings to the output then 3 would be the better way to approach the problem.
J4amieC wrote:
number 1 is the wrong way
Not at all. There is absolutely nothing wrong with using the Concat method to concatenate strings.
J4amieC wrote:
If it did assign str.ToString() to lblScore then it would be mostly the same as 2, but with the worthless overhead of creating a StringBuilder.
That is exactly how the String.Format method does it. The method that you say is the "right way" also has the worthless overhead of creating a StringBuilder, so you contradict yourself...
Despite everything, the person most likely to be fooling you next is yourself.
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Number 2 is the right way, number 1 is the wrong way and number 3 does something entirely different to 1 & 2 (It does not assign a variable to lblScore). If it did assign str.ToString() to lblScore then it would be mostly the same as 2, but with the worthless overhead of creating a StringBuilder. If however you were appending a greater number of strings to the output then 3 would be the better way to approach the problem.
Actually, #1 is the best way for his situation. A concatenation of up to 12 strings is much faster than either a StringBuilder or String.Format. StringBuilder incurrs overhead by keeping the strings on the heap until you call ToString(). String.Format has a variety of processing overhead that is not necessary in this case. When you know explicitly the number of string parts you need to join, and the order they will be joined in, a concat (up to 12 parts) will always be faster...significantly less overhead. Contrary to popular opinion, a single memory allocation and concat operation is involved in small concatenations. Only use an alternative method when the number of parts and/or their join order is unknown, or when you have more than 12 parts to join.
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Compiler changing concatenation with + to a stringbuilder asside, there is never a good reason to concatenate strings using +. Ever.
That is a COMPLETELY INVALID statement...I can't tell you how wrong that is. StringBuilder and String.Format are only useful and more performant in certain scenarios, not all. If you are joining thousands of string parts, StringBuilder will definitely be more efficient. If you are "formatting" a string, and you need localization support and the like, String.Format is your friend. However, for smaller concatenations where you know the number of parts involved, nothing beats the performance of a basic concat. Research it.
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Actually, #1 is the best way for his situation. A concatenation of up to 12 strings is much faster than either a StringBuilder or String.Format. StringBuilder incurrs overhead by keeping the strings on the heap until you call ToString(). String.Format has a variety of processing overhead that is not necessary in this case. When you know explicitly the number of string parts you need to join, and the order they will be joined in, a concat (up to 12 parts) will always be faster...significantly less overhead. Contrary to popular opinion, a single memory allocation and concat operation is involved in small concatenations. Only use an alternative method when the number of parts and/or their join order is unknown, or when you have more than 12 parts to join.
My apologies...a string concat requires 2 allocations, not 1. For a comparison of concat vs. StringBuilder, take a look at this article: http://blogs.msdn.com/ricom/archive/2004/03/12/performance-quiz-1-of-a-series.aspx Concat: 4 calls, 2 allocations, 94 bytes StringBuilder: 30 calls, 5 allocations, 184 bytes
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humayunlalzad wrote:
Can you tell me why concatenating strings is not a good idea in this case.
Concatenate 10,000 strings using + and time it. Now concatenate the same 10,000 strings using a stringbuilder. Compare the times.
J4amieC wrote:
Concatenate 10,000 strings using + and time it. Now concatenate the same 10,000 strings using a stringbuilder. Compare the times.
Here you go: Concatenating using + operator 10000 times: 3.50 ms. Concatenating using StringBuilder 10000 times: 5.03 ms. Concatenating using String.Format 10000 times: 5.97 ms.
Despite everything, the person most likely to be fooling you next is yourself.
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Mark Nischalke wrote:
I see nothing wrong with something like "Some string: " + x
I see nothing right with it, and no reason to use it over either of:
String.Format("Some string: {0}",x)orString.Concat("Some string: ",x) -
Hi All Is there any difference in the following three strings. Is any one of them more preferred over the other two.
//concat string
lblScore.Text = correctNums.ToString() + "/" + numberOfTurns.ToString();//Or
//Format string
lblScore.Text = String.Format("{0}/{1}", correctNums, numberOfTurns);//Or
//Stringbuilder
StringBuilder str = new StringBuilder();
str.AppendFormat("{0}/{1}", correctNums, numberOfTurns);If that's all I'm doing I use the second, but with more line breaks. I wouldn't be concerned about the relative efficiency of those particular statements; particularly when dealing with a GUI. But that's just me.