我对处理信息解析文本的不同方法了解很多。例如，对于解析整数，可以期望什么样的性能。我想知道是否有人知道这一点。我正在从测试过的人那里寻找一些实数。
在哪种情况下，哪一个提供最佳性能？
Parse(...) // Crash if the case is extremely rare .0001%
If (SomethingIsValid) // Check the value before parsing
Parse(...)
TryParse(...) // Using TryParse
try
{
Parse(...)
}
catch
{
// Catch any thrown exceptions
}
最佳答案
始终使用 T.TryParse(string str，out T value)。抛出异常的代价很高，如果可以先验地处理异常，则应避免抛出异常。使用try-catch块来“节省”性能(因为无效数据速率较低)会滥用异常处理，但会牺牲可维护性和良好的编码习惯。遵循良好的软件工程开发实践，编写测试案例，运行应用程序，然后进行基准测试并进行优化。
因此，像碳信用额度一样，您任意分配try-catch的性能较差，而TryParse的性能则更好。只有在运行应用程序并确定我们的速度有所下降之后字符串解析甚至可以考虑使用TryParse之外的任何其他方法。
(编辑:由于提问者似乎希望定时数据与好的建议一起使用，因此这是请求的定时数据)
用户(对于非信徒)10,000个输入上的各种故障率的时间:
Failure Rate Try-Catch TryParse Slowdown
0% 00:00:00.0131758 00:00:00.0120421 0.1
10% 00:00:00.1540251 00:00:00.0087699 16.6
20% 00:00:00.2833266 00:00:00.0105229 25.9
30% 00:00:00.4462866 00:00:00.0091487 47.8
40% 00:00:00.6951060 00:00:00.0108980 62.8
50% 00:00:00.7567745 00:00:00.0087065 85.9
60% 00:00:00.7090449 00:00:00.0083365 84.1
70% 00:00:00.8179365 00:00:00.0088809 91.1
80% 00:00:00.9468898 00:00:00.0088562 105.9
90% 00:00:01.0411393 00:00:00.0081040 127.5
100% 00:00:01.1488157 00:00:00.0078877 144.6
/// <param name="errorRate">Rate of errors in user input</param>
/// <returns>Total time taken</returns>
public static TimeSpan TimeTryCatch(double errorRate, int seed, int count)
{
Stopwatch stopwatch = new Stopwatch();
Random random = new Random(seed);
string bad_prefix = @"X";
stopwatch.Start();
for(int ii = 0; ii < count; ++ii)
{
string input = random.Next().ToString();
if (random.NextDouble() < errorRate)
{
input = bad_prefix + input;
}
int value = 0;
try
{
value = Int32.Parse(input);
}
catch(FormatException)
{
value = -1; // we would do something here with a logger perhaps
}
}
stopwatch.Stop();
return stopwatch.Elapsed;
}
/// <param name="errorRate">Rate of errors in user input</param>
/// <returns>Total time taken</returns>
public static TimeSpan TimeTryParse(double errorRate, int seed, int count)
{
Stopwatch stopwatch = new Stopwatch();
Random random = new Random(seed);
string bad_prefix = @"X";
stopwatch.Start();
for(int ii = 0; ii < count; ++ii)
{
string input = random.Next().ToString();
if (random.NextDouble() < errorRate)
{
input = bad_prefix + input;
}
int value = 0;
if (!Int32.TryParse(input, out value))
{
value = -1; // we would do something here with a logger perhaps
}
}
stopwatch.Stop();
return stopwatch.Elapsed;
}
public static void TimeStringParse()
{
double errorRate = 0.1; // 10% of the time our users mess up
int count = 10000; // 10000 entries by a user
TimeSpan trycatch = TimeTryCatch(errorRate, 1, count);
TimeSpan tryparse = TimeTryParse(errorRate, 1, count);
Console.WriteLine("trycatch: {0}", trycatch);
Console.WriteLine("tryparse: {0}", tryparse);
}
关于c# - 解析性能(If，TryParse，Try-Catch)，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/150114/