StringBuilder的是真的比Aggreggate快？ [英] Is StringBuilder really faster than Aggreggate?

问题描述

 串c = tmpArr [0] .Aggregate（的String.Empty，（目前，M）=>当前+（m.Name +））; 
 
 StringBuilder的SB =新的StringBuilder（）; 
 
的foreach（在tmpArr移动M [0]）
 sb.Append（m.Name +）; 
 
 sb.ToString（）; 
  

其中的两个是比较快？总肯定是清洁的，但它是快还是一样做

 的foreach（移动米tmpArr [0]） 
C + = m.Name +; 
  

我真正希望做的是一样的东西的string.join（ ，tmpArr [0]），但我不希望它Concat的自己的ToString值，只是他们的名字，我会怎么做，最好的？

我的问题，没有使用的string.join 是我居然会做这样的事情：

 字符串分隔符=; 
 StringBuilder的SB =新的StringBuilder（）; 
 
的foreach 
 {
隔板=，（在tmpArr [0]移动米）; 
 sb.Append（隔板+ m.Name）; 
} 
  

解决方案

 的string.join（，tmpArr [0]。选择（T => t.Name）.ToArray（））
  

但大部分时间的 它。只是。不。事！

        string c = tmpArr[0].Aggregate(string.Empty, (current, m) => current + (m.Name + " "));

        StringBuilder sb = new StringBuilder();

        foreach (Mobile m in tmpArr[0])
            sb.Append(m.Name + " ");

        sb.ToString();

which of those two is faster? aggregate certainly is cleaner, but is it fast or is it the same as doing

foreach(Mobile m in tmpArr[0])
    c += m.Name + " ";

what I really would like to do is something like string.Join(",",tmpArr[0]), but I don't want it to concat their ToString values, just their Names, how would I do that best?

my problem with not using string.Join is I would actually have to do something like this:

        string separator = "";
        StringBuilder sb = new StringBuilder();

        foreach (Mobile m in tmpArr[0])
        {
            separator = ", ";
            sb.Append(separator + m.Name);
        }

解决方案

I don't want it to concat their ToString values, just their Names, how would I do that best?

string.Join(",",tmpArr[0].Select(t => t.Name).ToArray())

But most of the time It. Just. Doesn't. Matter!

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