Exception handling in C++ technology: How to use try-catch blocks to handle exceptions?

The try-catch block in C is used to handle abnormal events beyond the program's expectations to prevent program errors or crashes. The syntax is: try {...} catch (const exception& e) {...}, where the try block is the code that may throw an exception, and the catch block is the code that handles the exception. Usage tips: Try to use try-catch in functions for exception handling; use specific exception classes to indicate exception types; avoid using empty statements in catch blocks; you can use multiple clauses in catch blocks to handle different exceptions; you can use std:: rethrow() rethrows an exception; using the noexcept keyword to declare a function will not throw an exception.

Exception handling in C technology: using try-catch blocks to handle exceptions

Exception is a kind of exception that occurs beyond the expectations of the program events that may cause program errors or crashes. C provides an exception handling mechanism to handle these exceptions.

try-catch block

The try-catch block is a control structure used to handle exceptions. Its syntax is as follows:

try { // 可能会抛出异常的代码 } catch (const exception& e) { // 处理异常的代码 }

Practical case

The following is a code example that uses a try-catch block to handle file opening exceptions:

#include  #include  using namespace std; int main() { ifstream file; try { file.open("test.txt"); if (!file.is_open()) throw runtime_error("文件打开失败"); // 文件处理代码 file.close(); } catch (const exception& e) { cout << "异常消息：" << e.what() << endl; } return 0; }

In In the code, we first try to open the file. If the file fails to open, it will throw aruntime_errorexception. We catch the exception in a catch block and print the exception message.

Use tips

• Use try-catch blocks in functions for exception handling whenever possible.
• Use specific exception classes to indicate specific exception types.
• Avoid using empty statements in catch blocks.
• A catch block can contain multiple catch clauses to handle different types of exceptions.
• You can usestd::rethrow()to rethrow an exception.
• Use thenoexceptkeyword to declare that a function will not throw an exception at compile time.

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