try-catch

问题 My question is really simple. Please take a look at screenshot: How could that happen? I explicitly put call to Async.RunSyncronously into try ... with . 回答1: try/with in F# async workflows do not map directly to CLR protected blocks - instead if exception is raised in user code, library code will catch it and re-route to the nearest error continuation (which can be i.e with block , finally block , custom error continuation supplied in Async.StartWithContinuations etc...). This has a

问题 I'm doing lottery game for my assignment (user inputs 6 number, i will generate 8 unique winning numbers and 2 last numbers are supplementary). I need help with user input checking if input numbers are from 1 to 45 and input must be int, when input is not integer it throws an error. This programming way is procedure way, how can i change it into object oriented way? I know that I must make methods in another java file and then link it back to this main. Can you suggest me how to do it? I have

问题 I'm building a dictionary of manufacturers. It would look something like this: mfgs = {17491: 'DS', 6543: 'AC'} In this scenario, I need to represent a range of integers that all refer to the same manufacturer. (e.g. 1 - 99 are all manufactured by DC) I've seen that you can create a dictionary key in which a range is represented. mfgs = {17491: 'DS', 6543: 'AC', (1,99): 'DC'} Later on, I will have an integer grabbed from an external file. Depending upon the value encountered, I will log the

问题 I'm trying to evaluate trees for a number of output parameters, in a loop. But sometimes the tree function aborts. How can the lines be surrounded by a try catch block? I apologize for not having "real" code, but I don't have an example of a non working tree. Here's pseddo code to illustrate the current implementation for (icol in seq(1,ncol)) { cName <-colnames(dt)[icol] tdata <- dt[,unique(c(1,2,icol)),with=F] nTrues <- sum(rowSums(tdata[,cName,with=F])) if (nTrues>0 ) { print(paste(

问题 I'm trying to evaluate trees for a number of output parameters, in a loop. But sometimes the tree function aborts. How can the lines be surrounded by a try catch block? I apologize for not having "real" code, but I don't have an example of a non working tree. Here's pseddo code to illustrate the current implementation for (icol in seq(1,ncol)) { cName <-colnames(dt)[icol] tdata <- dt[,unique(c(1,2,icol)),with=F] nTrues <- sum(rowSums(tdata[,cName,with=F])) if (nTrues>0 ) { print(paste(

问题 I have the following: public void method(){ try { methodThrowingIllegalArgumentException(); return; } catch (IllegalArgumentException e) { anotherMethodThrowingIllegalArgumentException(); return; } catch (IllegalArgumentException eee){ //1 //do some return; } catch (SomeAnotherException ee) { return; } } Java does not allow us to catch the exception twice, so we got compile-rime error at //1 . But I need to do exactly what I try to do: try the methodThrowingIllegalArgumentException() method

问题 I'm developing an Struts2-Hibernate dynamic web-based application, which makes the connection with database. As during establishing the connection, most of time I forgot to close the connection.So there is any way that I can achieve this with try-catch-resource . I have also gone through the javaDoc, but it raised my confusion. This is what I got from JavaDoc, please correct me if I'm wrong. Class which is having the connection code must implement AutoCloseable . This gives one method public

问题 Exceptions in C++ don't need to be caught (no compile time errors) by the calling function. So it's up to developer's judgment whether to catch them using try/catch (unlike in Java). Is there a way one can ensure that the exceptions thrown are always caught using try/catch by the calling function? 回答1: No. See A Pragmatic Look at Exception Specifications for reasons why not. The only way you can "help" this is to document the exceptions your function can throw, say as a comment in the header

问题 I'm wondering if there a way in Bluebird promises to .catch a thrown error and then process some specific actions without branching (nested promise). Say I have doSomethingAsync() .then(function (result) { if (!result) throw new CustomError('Blah Blah'); if (result == 0) throw new CustomError2('Blah Blah Blah'); return result; }) .then(function (result) { console.log('Success, great!'); }) .catch(CustomError, function (error) { // Oh CustomError! return saveSomethingAsync(); }) .then(function

问题 I have this piece of code: private void myFunc(){ obj = doSomething(); //If value is found, doX() //If value is not found, doY() } private obj doSomething(){ //Do some stuff //Hit database to get some value obj = db.getValue(); //This func throws an exception if no value is found } Now, my question is: 1. Should I do: doSomething() throws ValueNotFoundException and catch it in myFunc() 2. Or catch it in doSomething() and return null? (a very bad approach though). And then check for null in