如果将try/catch放在循环中，则会在异常发生后继续循环。如果你把它放在循环之外，你会在抛出异常时立即停止。

As already mentioned, the performance is the same. However, user experience isn't necessarily identical. In the first case, you'll fail fast (i.e. after the first error), however if you put the try/catch block inside the loop, you can capture all the errors that would be created for a given call to the method. When parsing an array of values from strings where you expect some formatting errors, there are definitely cases where you'd like to be able to present all the errors to the user so that they don't need to try and fix them one by one.

My perspective would be try/catch blocks are necessary to insure proper exception handling, but creating such blocks has performance implications. Since, Loops contain intensive repetitive computations, it is not recommended to put try/catch blocks inside loops. Additionally, it seems where this condition occurs, it is often "Exception" or "RuntimeException" which is caught. RuntimeException being caught in code should be avoided. Again, if if you work in a big company it's essential to log that exception properly, or stop runtime exception to happen. Whole point of this description is PLEASE AVOID USING TRY-CATCH BLOCKS IN LOOPS

为try/catch设置一个特殊的堆栈框架会增加额外的开销，但是JVM可能能够检测到您正在返回并优化它。

根据迭代次数的不同，性能差异可能可以忽略不计。

然而，我同意其他人的观点，把它放在循环之外会让循环体看起来更干净。

如果您希望继续处理，而不是在存在无效数字时退出，那么您将希望代码位于循环中。

如果你想在每个迭代中捕获Exception，或者检查哪个迭代抛出了Exception，并捕获迭代中的每个Exception，放置try…在循环内捕获。如果发生异常，这将不会中断循环，并且您可以在整个循环的每次迭代中捕获每个异常。

如果你想打破循环并在抛出异常时检查异常，请使用try…从循环中捕获。这将打破循环并在catch(如果有的话)之后执行语句。

这完全取决于你的需要。我更喜欢用try…如果Exception发生，结果不会有歧义，并且循环不会中断并完全执行。

把它放在里面。您可以继续处理(如果您愿意)，也可以抛出一个有用的异常，告诉客户端myString的值和包含坏值的数组的索引。我认为NumberFormatException已经告诉您坏的值，但原则是将所有有用的数据放在您抛出的异常中。考虑一下在程序的调试器中，您会对什么感兴趣。

考虑:

try {
   // parse
} catch (NumberFormatException nfe){
   throw new RuntimeException("Could not parse as a Float: [" + myString + 
                              "] found at index: " + i, nfe);
} 

在需要的时候，您将非常感谢这样一个异常，其中包含尽可能多的信息。